Introduction

Features Available

Used C#'s Generics

Used Nullable Datatype

Used Generics Collection IList To Bind GridView. 

Sorting Of Generics Collection IList Using IComparer Interface .

Applied Nullable Datatype function GetValueOrDefault for Sort Operation On Nullable Datafield.

Fully Tested Concurrent Sorting And Paging Operation In GridView.

Problem Statement

I had nullable value field data type in my database table. So I used nullable datatype of C# in my asp.net code. Doing so I encountered sorting failure problem with IComparer. After some research and development I came up with the solution. I used GetValueOrDefault() to resolve this. How I applied this to my solution is demonstrated below.
Consider Database table schema as:

Column	DataType	Nullable Values
CountryID	Int	No
CountryName	String	No
CountryTradeCode	Int	Yes

Implement IComparer:Business Entity Class Country

In below class we have three field as discussed. In this we have m_CountryTradeCode as nullable data type. I was facing problem sorting nullable data type. So I got a workaround for this as shown here.

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case CountryComparer.CountryComparisonType.CountryTradeCode:
                    
return this.m_CountryTradeCode.GetValueOrDefault().CompareTo(rhs.m_CountryTradeCode.GetValueOrDefault());

An important aspect to know about IComparer is that it operates on a complete Class Object and it knows about the object elements while IComparable operates only on elements of the object. The complete class is given below.

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public class Country
    {
        private int m_CountryID = int.MinValue;
        private string m_CountryName = string.Empty;
        private int? m_CountryTradeCode = null;

        public Country()
        {

        }
        public Country(int countryID)
        {
            m_CountryID = countryID;

        }
        public Country(int countryID, string countryName, int? countryTradeCode)
            : this(countryID)
        {
            m_CountryName = countryName;
            m_CountryTradeCode = countryTradeCode;
        }
        public int CountryID
        {
            get { return m_CountryID; }
            set { m_CountryID = value; }
        }
        public int? CountryTradeCode
        {
            get { return m_CountryTradeCode; }
            set { m_CountryTradeCode = value; }
        }
        public string CountryName
        {
            get { return m_CountryName; }
            set { m_CountryName = value; }
        }
        public int CompareTo(Country rhs, Country.CountryComparer.CountryComparisonType which)
        {
            switch (which)
            {
                case CountryComparer.CountryComparisonType.CountryID:
                    return this.m_CountryID.CompareTo(rhs.m_CountryID);
                case CountryComparer.CountryComparisonType.CountryName:
                    return this.m_CountryName.CompareTo(rhs.m_CountryName);
                case CountryComparer.CountryComparisonType.CountryTradeCode:
                    return this.m_CountryTradeCode.
GetValueOrDefault().CompareTo(rhs.m_CountryTradeCode.GetValueOrDefault());

            }
            return 0;
        }
        public class CountryComparer : IComparer< Country >
        {
            public enum CountryComparisonType
            {
                CountryID,
                CountryName,
                CountryTradeCode,
                NULL
            }
            private CountryComparisonType _whichComparison;
            private Utility.SortOrder _sortDirection;
            public CountryComparisonType WhichComparison
            {
                get { return _whichComparison; }
                set { _whichComparison = value; }
            }
            public int Compare(Country lhs, Country rhs)
            {
                if (SortDirection == Utility.SortOrder.Asc)
                    return lhs.CompareTo(rhs, WhichComparison);
                else
                    return rhs.CompareTo(lhs, WhichComparison);
            }
            public bool Equals(Country lhs, Country rhs)
            {
                return this.Compare(lhs, rhs) == 0;
            }
            public int GetHashCode(Country e)
            {
                return e.GetHashCode();
            }
            public Utility.SortOrder SortDirection
            {
                get { return _sortDirection; }
                set { _sortDirection = value; }
            }
        }
    }

Populate Collection List With Country Object

One can get this data from database using datareader and can populate this collection list as given below.For ready to go solution I have not used database and have hardcoded the values for understanding purpose. If you notice there is null fields in the objects that is been added as record in Collection List.The important challenge here is to sort this collection list having null value field. The nullable type is only applied to value type. As null reference is not assigned to value type,C# nullable datatype provide this feature.For eg. int a=null; is not allowed in C#. This is overcome by nullable datatype and the above example can be re written for nullable type as int? a = null;

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private IList GetCountryList()
        {
            IList < Country > countryList = new List < Country >();
            countryList.Add(new Country(1, "United States Of America", 100001));
            countryList.Add(new Country(2, "Africa", null));
            countryList.Add(new Country(3, "India", null));
            countryList.Add(new Country(4, "Singapore", 100004));
            countryList.Add(new Country(5, "Newzealand", 100005));
            countryList.Add(new Country(6, "United Kingdom", 100006));
            countryList.Add(new Country(7, "Australia", 100007));
            countryList.Add(new Country(8, "China", 100008));
            countryList.Add(new Country(9, "Malaysia", null));
            countryList.Add(new Country(10, "Germany", 100011));
            countryList.Add(new Country(11, "France", 100009));
            countryList.Add(new Country(12, "United States Of Soviet Russia", null));
            return countryList;
        }

C# Generics Method:Bind GridView Control

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private void BindGrid < T >(T list)
        {
            gridCountry.DataSource = list;
            gridCountry.DataBind();
        }

Sort Event Logic

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private void SortCountryList(Country.CountryComparer.CountryComparisonType sortExpression)
        {
            List < Country > countryList = (List < Country >)GetCountryList();
            Country.CountryComparer countryComparer = new Country.CountryComparer();
            if (Country.CountryComparer.CountryComparisonType.NULL != sortExpression)
            {
                if (sortExpression == SortColumn)
                {
                    if (SortDirection == Utility.SortOrder.Asc)
                    {
                        SortDirection = Utility.SortOrder.Desc;
                    }
                    else
                    {
                        SortDirection = Utility.SortOrder.Asc;
                    }
                }
                else
                {
                    SortDirection = Utility.SortOrder.Asc;
                }
                SortColumn = sortExpression;
            }
            countryComparer.WhichComparison = SortColumn;
            countryComparer.SortDirection = SortDirection;
            countryList.Sort(countryComparer);
            CountryDataSource = countryList;
        }

Concurrent paging And Sorting Operation On Grid

Contrary to what the title suggests,paging and sort operation here is not happening at the same time.The flow of the program suggests that the sorted order of a given column in a grid has to be maintained when paging operation is done.That means paging is carried out on sorted List.For this I used Viewstate to maintain the current operation.

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private Country.CountryComparer.CountryComparisonType SortColumn
        {
            get { return (Country.CountryComparer.CountryComparisonType)ViewState["SORT_EXP"]; }
            set { ViewState["SORT_EXP"] = value; }
        }
           
        private Utility.SortOrder SortDirection
        {
            get { return (Utility.SortOrder)ViewState["SORT_ORDER"]; }
            set { ViewState["SORT_ORDER"] = value; }
        }
       

Initially the list is loaded with current sort order and sort direction.

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protected void Page_Load(object sender, EventArgs e)
        {
            try
            {
                if (IsPostBack == false)
                {
                    SortColumn = Country.CountryComparer.CountryComparisonType.CountryID;
                    SortDirection = Utility.SortOrder.Asc;
                    LoadCountryList();
                }
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
        private void LoadCountryList()
        {
            SortCountryList(Country.CountryComparer.CountryComparisonType.NULL);
        }

This is called on page change event on sorted List.

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private void PagingCountryList()
        {
            SortCountryList(Country.CountryComparer.CountryComparisonType.NULL);
        }

One can download the code and can check the code for more understanding and usage purpose.

Conclusion

Hope I met the expectations of the reader and also please vote for this article ,this will help me to understand the quality I put in. Any suggestion and advice are most welcome. Looking forward for your feedback.

• Values are atomic.
• Column values are of the same kind.
• Each row is unique.
• The sequence of columns is insignificant.
• The sequence of rows is insignificant.
• Each column must have a unique name.

Introduction  

This article deals with -

• Query Optimizer  
• Creating an Index
• Creating Unique Index
• Creating Clustered Index
• Creating Full-Text Index
• Changing properties of Index
• Renaming an Index
• Deleting an Index
• Specifying Fill factor of Index
• Create XML Index
• Delete XML Index
• Advantages of Indexing
• Disadvantages of Indexing
• Guidelines for Indexing

Explanation

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SELECT CustomerID,ContactName,CompanyName,City
FROM Customers
WHERE Country ='USA'

Indexes may be either Clustered or Non-Clustered.

Clustered Index 

Non-Clustered Index

The Query Optimizer

Creating an Index

• Connect to Northwind database from Object Explorer, right click on the Customers table to create an index and click on modify. 

 

• Click on Index/Keys from Table Desinger Menu on top or right click on any column and click on Index/Keys.

 

• Click on Add from Indexes/Keys dialog box.

• From Selected Primary/Unique Key or Index list, select the new index and set properties for the index in the grid on right hand side.  

• Now just specify other settings if any for the index and click Close.
• When we save the table, the index is created in the database. 

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 CREATE INDEX Country ON Customers (Country) 

Creating Unique Index

• Right-click on the Customers and click Modify in Object Explorer.
• Now, click on Indexes/Keys from Table Designer menu and click on Click Add.
• The Selected Primary/Unique Key or Index list displays the automatically generated name of the new index.  
• In the grid, click on Type, from the drop-down list, Choose Index.
• Under Column name,we can choose columns we want to index and click on OK. Maximum we can setup 16 columns. For optimum performance, it is recommended that we use one or two columns per index. For every column we values of these columns are arranged in ascending or descending order.  
• In the grid, click Is Unique and select select Yes. 

• Null is treated as duplicate values. So, it is not possible to create unique index on one column if it contains null in more than one row. Likewise index cannot be created on multiple columns if those columns contains null in same row.
• Now select Ignore duplicate keys option. If it is required to ignore new or updated data that will lead to creation of duplicate key in the index (with the INSERT or UPDATE statement).
• When we save the table, the index is created in the database.

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CREATE UNIQUE INDEX ContactName ON Customers (CompanyName,ContactName) 

Creating Clustered Index

• In the Object Explorer click on the Northwind database, right click on the Customres to create an index and click on modify.
• Now we have Table Designer for the table.
• From the Table Designer menu, click Indexes/Keys and from Indexes/Keys dialog box, click Add. 
• Now from Selected Primary/Unique Key or Index list, Select the new index
• In the grid, select Create as Clustered, and choose Yes from the drop-down list to the right of the property.  

• When we save the table, the index is created in the database.

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CREATE CLUSTERED INDEX PK_Customers on Customers(CustomerID)

Creating Full Text Search 

• In the object explorer click on the Northwind database, right click on the customers to create an index and click on modify.
• Now, we have Table Designer for the customers table and then Click Fulltext Index from the Table Designer menu.

 

• Dialog box for full-text index opens. (Sometimes database is not enabled for full text indexing. In such situations add button disabled. To enable it check properties for database by right clicking on database. And check the full text indexing check box)
• Now we have to right click on storage>New Full-Text catalog to create a catalog. Enter some required information in dialog box.  

• Now from Table Designer menu, open the Full Text Index property dialog and then click on Add.
• Now select new index from selected full-text index list and assign properties for index in the grid.  

• When we save Table the index is automatically saved in database, and this index is available for modifications.

Changing index properties

• Connect to the SQL-Server 2005, In the object explorer click on the Northwind database.
• Click Indexes/Keys from the table designer menu.
• Now select index from the selected primary/unique key or index list. And Change the properties.
• When we save Table the index is automatically saved in database.

Renaming an Index

• Right-click the table with the index you want to rename and click Modify, in Object Explorer.
• Click Indexes/Keys from the Table Designer menu.
• Now from the Selected Primary/Unique Key or Index list, select the index.
• Click Name and type a new name into the text box in the grid.
• When we save Table the index is automatically saved in database.

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EXEC sp_rename 'Customers.Country', 'Countries'

Deleting an Index  

• Right-click the table with indexes you want to delete and click Modify In Object Explorer.
• Click Indexes/Keys from the Table Designer menu.  
• Select the index you want to delete from the Indexes/Keys dialog box and Click on Delete.
• When we save Table the index is deleted from the database.

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DROP Index Customers.Country  

Specifying Fill Factor

• Right-click the table with an index for which we want to specify fill factor and click Modify in Object Explorer
• Click Indexes/Keys, from the Table Designer menu.
• From Selected Primary/Unique Key or Index list, select the index.
• Type a number from 0 to 100, in the Fill Factor box. Value 100 denotes that index will fully filled up and storage space requirement will be minimum, this is recommended in situations where there are minimum changes of change in data. data fill factor. If there is regular modification and addition to the data, then set this value to minimum. Storage space is proportionate to the value set.

 

Creating XML Index

• In Object Explorer, right-click the customers table to create an XML index and click Modify.  

• Select the xml column for the index for the table opened in Table Designer.
• From the Table Designer menu, click XML Index,  
• Click on add, in the XML Indexes dialog box  

Deleting XML Indexes 

• Right-click the customers table with the XML index you want to delete and click Modify in Object Explorer.  
• click on XML Index, from the Table Designer menu.
• From selected XML Index column, Click the index you want to delete. And then Click on Delete.

Viewing Existing Indexes

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EXEC sp_helpindex Customers

How Index works 

Searching For Records  

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DELETE FROM Customers WHERE Country = "USA"
 UPDATE Customers SET Region = "Pacific" WHERE Country = "USA" 
 SELECT * FROM Customers WHERE Country="USA" or "Brasil"

Sorting Records

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SELECT * FROM Customers ORDER BY Country ASC

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SELECT * FROM Customers ORDER BY Country DESC

Grouping Records

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SELECT Count(*) FROM Products GROUP BY UnitPrice

Index Drawbacks

Indexes and Disk Space

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name                rows        reserved           data               index_size         unused
---------        ----------- ------------------ ------------------ ------------------ 
Customers        91          200 KB             24 KB              176 KB             0 KB

Indexes and Data Modification

Additional Index Guidelines

Keeping Index Keys Short

Distinct Index Keys

Conclusion 

<script Language="JavaScript">
<!--
function Form1_Validator(theForm)
{

var alertsay = ""; // define for long lines
// alertsay is not necessary for your code,
// but I need to break my lines in multiple lines
// so the code won't extend off the edge of the page

// check to see if the field is blank
if (theForm.Alias.value == "")
{
alert("You must enter an alias.");
theForm.Alias.focus();
return (false);
}

// require at least 3 characters be entered
if (theForm.Alias.value.length < 3)
{
alert("Please enter at least 3 characters in the \"Alias\" field.");
theForm.Alias.focus();
return (false);
}

// allow ONLY alphanumeric keys, no symbols or punctuation
// this can be altered for any "checkOK" string you desire
var checkOK = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
var checkStr = theForm.Alias.value;
var allValid = true;
for (i = 0;  i < checkStr.length;  i++)
{
ch = checkStr.charAt(i);
for (j = 0;  j < checkOK.length;  j++)
if (ch == checkOK.charAt(j))
break;
if (j == checkOK.length)
{
allValid = false;
break;
}
}
if (!allValid)
{
alert("Please enter only letter and numeric characters in the \"Alias\" field.");
theForm.Alias.focus();
return (false);
}

// require at least 5 characters in the password field
if (theForm.Password.value.length < 5)
{
alert("Please enter at least 5 characters in the \"Password\" field.");
theForm.Password.focus();
return (false);
}

// check if both password fields are the same
if (theForm.Password.value != theForm.Password2.value)
{
	alert("The two passwords are not the same.");
	theForm.Password2.focus();
	return (false);
}

// allow only 150 characters maximum in the comment field
if (theForm.comment.value.length > 150)
{
alert("Please enter at most 150 characters in the comment field.");
theForm.comment.focus();
return (false);
}

// check if no drop down has been selected
if (theForm.sex.selectedIndex < 0)
{
alert("Please select one of the \"Gender\" options.");
theForm.sex.focus();
return (false);
}

// check if the first drop down is selected, if so, invalid selection
if (theForm.sex.selectedIndex == 0)
{
alert("The first \"Gender\" option is not a valid selection.");
theForm.sex.focus();
return (false);
}

// check if no drop down or first drop down is selected, if so, invalid selection
if (theForm.date_month.selectedIndex <= 0)
{
alert("Please select a month.");
theForm.date_month.focus();
return (false);
}

// check if no drop down or first drop down is selected, if so, invalid selection
if (theForm.date_day.selectedIndex <= 0)
{
alert("Please select a day.");
theForm.date_day.focus();
return (false);
}

// check if no drop down or first drop down is selected, if so, invalid selection
if (theForm.date_year.selectedIndex <= 0)
{
alert("Please select a year.");
theForm.date_year.focus();
return (false);
}

// check if email field is blank
if (theForm.Email.value == "")
{
alert("Please enter a value for the \"Email\" field.");
theForm.Email.focus();
return (false);
}


// test if valid email address, must have @ and .
var checkEmail = "@.";
var checkStr = theForm.Email.value;
var EmailValid = false;
var EmailAt = false;
var EmailPeriod = false;
for (i = 0;  i < checkStr.length;  i++)
{
ch = checkStr.charAt(i);
for (j = 0;  j < checkEmail.length;  j++)
{
if (ch == checkEmail.charAt(j) && ch == "@")
EmailAt = true;
if (ch == checkEmail.charAt(j) && ch == ".")
EmailPeriod = true;
	  if (EmailAt && EmailPeriod)
		break;
	  if (j == checkEmail.length)
		break;
	}
	// if both the @ and . were in the string
if (EmailAt && EmailPeriod)
{
		EmailValid = true
		break;
	}
}
if (!EmailValid)
{
alert("The \"email\" field must contain an \"@\" and a \".\".");
theForm.Email.focus();
return (false);
}


// check if numbers field is blank
if (theForm.numbers.value == "")
{
alert("Please enter a value for the \"numbers\" field.");
theForm.numbers.focus();
return (false);
}

// only allow numbers to be entered
var checkOK = "0123456789";
var checkStr = theForm.numbers.value;
var allValid = true;
var allNum = "";
for (i = 0;  i < checkStr.length;  i++)
{
ch = checkStr.charAt(i);
for (j = 0;  j < checkOK.length;  j++)
if (ch == checkOK.charAt(j))
break;
if (j == checkOK.length)
{
allValid = false;
break;
}
if (ch != ",")
allNum += ch;
}
if (!allValid)
{
alert("Please enter only digit characters in the \"numbers\" field.");
theForm.numbers.focus();
return (false);
}

// require at least one radio button be selected
var radioSelected = false;
for (i = 0;  i < theForm.fruit.length;  i++)
{
if (theForm.fruit[i].checked)
radioSelected = true;
}
if (!radioSelected)
{
alert("Please select one of the \"Fruit\" options.");
return (false);
}

// check if no drop down or first drop down is selected, if so, invalid selection
if (theForm.rangefrom.selectedIndex <= 0)
{
alert("Please select a valid number in the range \"From\" field.");
theForm.rangefrom.focus();
return (false);
}

// check if no drop down or first drop down is selected, if so, invalid selection
if (theForm.rangeto.selectedIndex <= 0)
{
alert("Please select a valid number in the range \"To\" field.");
theForm.rangeto.focus();
return (false);
}

// require that the To Field be greater than or equal to the From Field
var chkVal = theForm.rangeto.value;
var chkVal2 = theForm.rangefrom.value;
if (chkVal != "" && !(chkVal >= chkVal2))
{
alert("The \"To\" value must be greater than or equal to (>=) the \"From\" value.");
theForm.rangeto.focus();
return (false);
}

// check if more than 5 options are selected
// check if less than 1 options are selected
var numSelected = 0;
var i;
for (i = 0;  i < theForm.province.length;  i++)
{
if (theForm.province.options[i].selected)
numSelected++;
}
if (numSelected > 5)
{
alert("Please select at most 5 of the \"province\" options.");
theForm.province.focus();
return (false);
}
if (numSelected < 1)
{
alert("Please select at least 1 of the \"province\" options.");
theForm.province.focus();
return (false);
}

// require a value be entered in the field
if (theForm.NumberText.value == "")
{
alert("Please enter a value for the \"NumberText\" field.");
theForm.NumberText.focus();
return (false);
}

// require that at least one character be entered
if (theForm.NumberText.value.length < 1)
{
alert("Please enter at least 1 characters in the \"NumberText\" field.");
theForm.NumberText.focus();
return (false);
}

// don't allow more than 5 characters be entered
if (theForm.NumberText.value.length > 5)
{
	 alertsay = "Please enter at most 5 characters in "
	 alertsay = alertsay + "the \"NumberText\" field, including comma."
alert(alertsay);
theForm.NumberText.focus();
return (false);
}

// only allow 0-9, hyphen and comma be entered
var checkOK = "0123456789-,";
var checkStr = theForm.NumberText.value;
var allValid = true;
var decPoints = 0;
var allNum = "";
for (i = 0;  i < checkStr.length;  i++)
{
ch = checkStr.charAt(i);
for (j = 0;  j < checkOK.length;  j++)
if (ch == checkOK.charAt(j))
break;
if (j == checkOK.length)
{
allValid = false;
break;
}
if (ch != ",")
allNum += ch;
}
if (!allValid)
{
alert("Please enter only digit characters in the \"NumberText\" field.");
theForm.NumberText.focus();
return (false);
}

// require a minimum of 9 and a maximum of 5000
// allow 5,000 (with comma)
var chkVal = allNum;
var prsVal = parseInt(allNum);
if (chkVal != "" && !(prsVal >= "9" && prsVal <= "5000"))
{
	alertsay = "Please enter a value greater than or "
	alertsay = alertsay + "equal to \"9\" and less than or "
	alertsay = alertsay + "equal to \"5000\" in the \"NumberText\" field."
alert(alertsay);
theForm.NumberText.focus();
return (false);
}

// alert if the box is NOT checked
if (!theForm.checkbox1.checked)
{
alertsay = "Just reminding you that if you wish "
alertsay = alertsay + "to have our Super Duper option, "
alertsay = alertsay + "you must check the box!"
alert(alertsay);
}

// require that at least one checkbox be checked
var checkSelected = false;
for (i = 0;  i < theForm.checkbox2.length;  i++)
{
if (theForm.checkbox2[i].checked)
checkSelected = true;
}
if (!checkSelected)
{
alert("Please select at least one of the \"Test Checkbox\" options.");
return (false);
}

// only allow up to 2 checkboxes be checked
var checkCounter = 0;
for (i = 0;  i < theForm.checkbox2.length;  i++)
{
if (theForm.checkbox2[i].checked)
checkCounter = checkCounter + 1;
}
if (checkCounter > 2)
{
alert("Please select only one or two of the \"Test Checkbox\" options.");
return (false);
}

// because this is a sample page, don't allow to exit to the post action
// comes in handy when you are testing the form validations and don't
// wish to exit the page
alertsay = "All Validations have succeeded. "
alertsay = alertsay + "This is just a test page. There is no submission page."
alert(alertsay);
return (false);
// replace the above with return(true); if you have a valid form to submit to
}
//--></script>

<form action="javascript.asp?ID=<%=siteID%>"
method="POST" onsubmit="return Form1_Validator(this)" name="Form1">
<input type="submit" name="Submit" value="Submit"><p>

Alias:
	<input type="text" size="15" maxlength="15" name="Alias"><br>
	3 checks:
	Not blank, at least 3 characters, only alphanumeric characters allowed.<p>

Password:
	<input type="password" size="10" maxlength="10" name="Password">

Verify Password:
	<input type="password" size="10" maxlength="10" name="Password2"><br>
	2 checks: Require at least 5 characters in the first password field.
	Check if both password field values are the same.<p>

Comment: (Please enter 150 characters maximum.)<br>
<textarea name="comment" rows="4" cols="50" wrap="virtual">
</textarea><br>

Gender:
	<select name="sex" size="1">
<option>Select a Gender</option>
<option value="M">Male</option>
<option value="F">Female</option>
</select><br>
2 checks: Check that at least one drop down has been selected.
The first drop down is an invalid selection.<p>

Date Month:
	<select NAME="date_month">
		<option VALUE="0">
		<option VALUE="1">1
		<option VALUE="2">2
		<option VALUE="3">3
		<option VALUE="4">4
		<option VALUE="5">5
		<option VALUE="6">6
		<option VALUE="7">7
		<option VALUE="8">8
		<option VALUE="9">9
		<option VALUE="10">10
		<option VALUE="11">11
		<option VALUE="12">12		
	</select>
	 
	Day:
	<select NAME="date_day">
		<option VALUE="0">
		<option VALUE="1">1
		<option VALUE="2">2
		<option VALUE="3">3
		<option VALUE="4">4
		<option VALUE="5">5
		<option VALUE="6">6
		<option VALUE="7">7
		<option VALUE="8">8
		<option VALUE="9">9
		<option VALUE="10">10
		<option VALUE="11">11
		<option VALUE="12">12
		<option VALUE="13">13
		<option VALUE="14">14
		<option VALUE="15">15
		<option VALUE="16">16
		<option VALUE="17">17
		<option VALUE="18">18
		<option VALUE="19">19
		<option VALUE="20">20
		<option VALUE="21">21
		<option VALUE="22">22
		<option VALUE="23">23
		<option VALUE="24">24
		<option VALUE="25">25
		<option VALUE="26">26
		<option VALUE="27">27
		<option VALUE="28">28
		<option VALUE="29">29
		<option VALUE="30">30
		<option VALUE="31">31		
	</select>
	 
	Year:
	<select NAME="date_year">
		<option VALUE="0">
		<option VALUE="2000">2000
		<option VALUE="1999">1999
		<option VALUE="1998">1998
		<option VALUE="1997">1997
		<option VALUE="1996">1996
		<option VALUE="1995">1995
		<option VALUE="1994">1994
		<option VALUE="1993">1993
		<option VALUE="1992">1992
		<option VALUE="1991">1991
		<option VALUE="1990">1990
	</select>
<br>
2 checks: Check that at least one drop down has been selected.
The first drop down is an invalid selection.<p>

Email:
	<input type="text" size="60" name="Email" value><br>
	2 checks: Can't be blank. A valid email address must contain an "@"
	and a "." in the address.<p>

<input type="submit" name="Submit" value="Submit"> <p>

Numbers:</strong>
	<input type="text" size="3" maxlength="3" name="numbers"><br>
	2 checks: Can't be blank. Only numbers 0-9 accepted.<p>

Fruit<br>
	<input type="radio" name="fruit" value="A"> A. Apples<br>
	<input type="radio" name="fruit" value="B"> B. Oranges<br>
	<input type="radio" name="fruit" value="C"> C. Pears<br>
<input type="radio" name="fruit" value="D"> D. Lemons<br>
1 check: At least one radio button must be selected.<p>
<br>

Range From:
		<select NAME="rangefrom">
		<option VALUE="0" selected>
		<option VALUE="1">1
		<option VALUE="2">2
		<option VALUE="3">3
		<option VALUE="4">4
		<option VALUE="5">5
		<option VALUE="6">6
		<option VALUE="7">7
		<option VALUE="8">8
		<option VALUE="9">9
		</select>

	To:
		<select NAME="rangeto">
		<option VALUE="0" selected>
		<option VALUE="1">1
		<option VALUE="2">2
		<option VALUE="3">3
		<option VALUE="4">4
		<option VALUE="5">5
		<option VALUE="6">6
		<option VALUE="7">7
		<option VALUE="8">8
		<option VALUE="9">9
		</select><br>
3 checks: Must select at least one option from both the From and the To fields.
The FROM value must be less than or equal to the TO value.<p>

Select 1-5 Provinces: (0 or more than 5 not allowed)<br>		
	<select NAME="province" size="5" MULTIPLE>
		<option value="AB">
		Alberta, Canada
		</option>
		<option value="BC">
		British Columbia, Canada
		</option>
		<option value="MB">
		Manitoba, Canada
		</option>
		<option value="NB">
		New Brunswick, Canada
		</option>
		<option value="NF">
		Newfoundland, Canada
		</option>
		<option value="NS">
		Nova Scotia, Canada
		</option>
		<option value="ON">
		Ontario, Canada
		</option>
		<option value="PE">
		Prince Edward Island, Canada
		</option>
		<option value="PQ">
		Quebec, Canada
		</option>
		<option value="SK">
		Saskatchewan, Canada
		</option>
		<option value="YT">
		Yukon - N.W.T., Canada
		</option>
	</select>
<br>2 checks: At least 1 option must be selected.
No more than 5 options may be selected.
<p>
Number between 9 and 5000. Accepts commas:
Enter a number: <input type="text" size="5" maxlength="5" name="NumberText"><br>
5 checks: Cannot be blank. Must enter at least one character.
Can't enter more than 5 characters, including comma.
Must be between 9 and 5000. Accepts numbers, commas and hyphens,
so allows up to 5 characters for text field maxlength.<p>

Check Box: <input type="checkbox" name="checkbox1" value="Y"><br>
1 check: Reminds the user they have not checked the box.
Does not fail the validation however.<p>

Test Boxes: Check at least 1. No more than 2.
<input type="checkbox" name="checkbox2" value="1">Test1
<input type="checkbox" name="checkbox2" value="2">Test2
<input type="checkbox" name="checkbox2" value="3">Test3 <br>
2 checks: Requires at least one of the 3 checkboxes be selected.
Only allows a maximum of 2 boxes to be selected.<p>
<p>

<input type="submit" name="Submit" value="Submit">
<input type="reset" name="Reset" value="Reset"><p>
</form>