how to display a grid using on click event

Imports System.Data
Imports System.Data.SqlClient
Partial Class MergedHeaderHeight
    Inherits System.Web.UI.Page
  



#Region "RenderHeader Enquiry Details"
    Private Sub RenderHeader(ByVal writer As System.Web.UI.HtmlTextWriter, ByVal ctl As System.Web.UI.Control)

        'We don't need to write the <TR> tag because it's already written by the writer
        'so now we write the Name column
        writer.Write("<TD align=center colspan=2 class='ghdr'>Employee</TD>")
        writer.Write("<TD align=center border=0 ROWSPAN=2 class='ghdr'>SALARY</TD>")
        writer.Write("<TD align=center colspan=2 class='ghdr'>Employee</TD>")
        writer.Write("<TD align=center border=0 ROWSPAN=2 class='ghdr'>SALARY</TD>")

        'Now we close the first row, so we can insert the second one
        writer.Write("</TR>")

        'Add the style attributes that was defined in design time
        'to our second row so they both will have the same appearance
        iFlexGrid1.HeaderStyle.AddAttributesToRender(writer)

        'Insert the second row
        writer.Write("<TR>")

        Dim iLoop As Integer
        For iLoop = 0 To ctl.Controls.Count - 1
            If iLoop = 0 Or iLoop = 1 Or iLoop = 3 Or iLoop = 4 Then
                CType(ctl.Controls.Item(iLoop), WebControl).CssClass = "ghdr"
                ctl.Controls.Item(iLoop).RenderControl(writer)
            End If
        Next
        writer.Write("</TR>")
        'We don't need to write the </TR> close tag because the writer will do that for us
        'and so we're done :)
    End Sub
#End Region

 



    Protected Sub iFlexGrid1_Load(sender As Object, e As System.EventArgs) Handles iFlexGrid1.Load
        Dim strconn = ConfigurationManager.AppSettings("Test").ToString()
        Dim sql As String = "select * from tab1"
        Dim da As New SqlDataAdapter(Sql, strconn)
        Dim dt As New DataTable()
        da.Fill(dt)
        iFlexGrid1.DataSource = dt
        iFlexGrid1.DataBind()
    End Sub

    Protected Sub iFlexGrid1_RowCreated(ByVal sender As Object, ByVal e As iInterchange.WebControls.v4.Data.iFlexGridRowEventArgs) Handles iFlexGrid1.RowCreated
        If e.Row.RowType = DataControlRowType.Header Then
            e.Row.SetRenderMethodDelegate(New RenderMethod(AddressOf RenderHeader))
        End If
    End Sub



End Class