Forms Data Controls :: Paging In Gridview Control Asp.net 2.0, MySQL

I am a new user of ASP.NET 2.0 (VB.NET)
I am facing a problem related to GridView Control

I have a table <UsersDetail> with following structure in MySQL

FIELDNAME | DATATYPE
---------------------------------------
userid | Numeric
Userlogin | Varchar(25)
Userpassword | Varchar(25)
Firstname | Varchar(50)
Lastname | Varchar(50)
---------------------------------------

I wrote a code to fetch data from this table :

Dim Con As New MySqlConnection
Dim Cmd As New MySqlCommand
Dim Adp As New MySqlDataAdapter
Dim DTable As DataTable
Con.ConnectionString = ConfigurationManager.ConnectionStrings("dbConString").ConnectionString
Cmd.CommandType = CommandType.StoredProcedure
Cmd.CommandText = "sp_FetchAllUsers"
Cmd.Connection = Con
Adp = New MySqlDataAdapter
Adp.SelectCommand = Cmd
DTable = New DataTable
Adp.Fill(DTable)
GridView1.DataSource = DTable
GridView1.DataBind()

Basically Gridview controls is used to display data in tabular format.
but due to requirement I changed its layout to columner in following manner

<asp:GridView ID="myGridView" runat="server" AutoGenerateColumns="false" AllowPaging="True" PageSize="3" Width="520px">
<Columns>
<asp:TemplateField HeaderText="User ID">
<ItemTemplate>
<asp:Label ID="Label3" Text='<%#Eval("userid") %>' runat="server"></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="User Login">
<ItemTemplate>
<asp:Label ID="Label4" Text='<%#Eval("Userlogin") %>' runat="server"></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Pack Amount">
<ItemTemplate>
<asp:Label ID="Password" Text='<%#Eval("Userpassword") %>' runat="server"></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="For">
<ItemTemplate>
<asp:Label ID="First name" Text='<%#Eval("Firstname") %>' runat="server"></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Validity">
<ItemTemplate>
<asp:Label ID="Last name" Text='<%#Eval("Lastname") %> Months' runat="server"></asp:Label>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>

Now come to the problem, i set the AllowPaging="True" and page size to 3 records/page but when click on paging links it displays the following error :

The GridView 'myGridView' fired event PageIndexChanging which wasn't handled.

Description:
An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Web.HttpException: The GridView 'myGridView' fired event PageIndexChanging which wasn't handled.

Source Error:

[Code]....