<asp:TemplateColumn HeaderText="Category" SortExpression="CTGY_NBR">
<HeaderStyle Width="6%"></HeaderStyle>
<ItemTemplate>
<asp:LinkButton Runat="server" ID="lnkCategory"
CommandName="CatDrillDown" CommandArgument='<%#
container.dataitem("CTGY_NBR") %>' >
<%# container.dataitem("CTGY_NBR") %>
</asp:LinkButton>
</ItemTemplate>
</asp:TemplateColumn>

Private Sub ImgbtnExport_Click(ByVal sender As System.Object, ByVal e As System.Web.UI.ImageClickEventArgs) Handles ImgBtnExport.Click
        Dim objExport As New clsDS()
        Try
            If dg.Visible = True Then
                objExport.ExportToExcel(dg, Response, "Weekly Store OOS by Category")
            Else
                objExport.ExportToExcel(dgCtgy, Response, "Weekly Store OOS by Category")
            End If
        Catch ex As Exception
            Handleerror(ex)
        Finally
            objExport = Nothing
        End Try
    End Sub

Public Sub ExportToExcel(ByVal dg As DataGrid, _
                           ByVal aResponse As HttpResponse, _
                           Optional ByVal asFilename As String = "")
        Try
            aResponse.Clear()
            aResponse.ContentType = "application/vnd.ms-excel"
            aResponse.AddHeader("Content-Disposition", "attachment;filename=" & asFilename & ".xls;")
            aResponse.Charset = ""
            Dim tw As New System.IO.StringWriter()
            Dim hw As New System.Web.UI.HtmlTextWriter(tw)
            dg.GridLines = GridLines.Both
            Me.ClearControls(dg)
            dg.HeaderStyle.Font.Bold = True
            dg.RenderControl(hw)
            dg.GridLines = GridLines.Both
            aResponse.Write(tw.ToString())
            
            aResponse.Flush()
            aResponse.Close()
        Catch err As Exception
            Throw err
        End Try
    End Sub