Exporting to Excell Help(ASP.net/VB.net)

I have the following sub to export to excell. The problem is this :

The below code used to work when I had bound columns, but now I have template columns like this :

<asp:TemplateColumn HeaderText="Job #">
       <HeaderStyle Width="16%"></HeaderStyle>
<ItemTemplate>
<asp:Label id="Label1" runat="server" Text='<%# DataBinder.Eval(Container, "DataItem.job_id") %>'>
</asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox Wrap=True id="Textbox1" runat="server" Text='<%# DataBinder.Eval(Container, "DataItem.job_id") %>' Width="100%">
</asp:TextBox>
</EditItemTemplate>
</asp:TemplateColumn>


obviously this doesnt work anymore :

        For Each item In DataGrid1.Items
            colRow = item.Cells(0).Text & Chr(9) & item.Cells(1).Text & Chr(9) & item.Cells(2).Text & Chr(9) & item.Cells(3).Text & Chr(9) & item.Cells(4).Text & Chr(9) & item.Cells(5).Text & Chr(9) & item.Cells(6).Text & Chr(9) & item.Cells(7).Text & Chr(9) & item.Cells(8).Text & Chr(9) & item.Cells(9).Text & Chr(9) & item.Cells(10).Text & Chr(9) & item.Cells(11).Text & Chr(9) & item.Cells(12).Text & Chr(9) & item.Cells(13).Text & Chr(9) & item.Cells(14).Text & Chr(13) & Chr(10)
            resp.Write(colRow)
        Next item

so I tried :

For Each item In DataGrid1.Items
            colRow = CType(item.Cells(0).FindControl("Textbox1"), TextBox).Text & Chr(9) & CType(item.Cells(1).FindControl("Textbox2"), TextBox).Text & Chr(9) & CType(item.Cells(2).FindControl("Textbox3"), TextBox).Text & Chr(9) & CType(item.Cells(3).FindControl("Textbox4"), TextBox).Text & Chr(9) & CType(item.Cells(4).FindControl("Textbox5"), TextBox).Text & Chr(9) & CType(item.Cells(5).FindControl("Textbox6"), TextBox).Text & Chr(9) & CType(item.Cells(6).FindControl("Textbox7"), TextBox).Text & Chr(9) & CType(item.Cells(7).FindControl("Textbox8"), TextBox).Text & Chr(9) & CType(item.Cells(8).FindControl("Textbox9"), TextBox).Text & Chr(9) & CType(item.Cells(9).FindControl("Textbox10"), TextBox).Text & Chr(9) & CType(item.Cells(10).FindControl("Textbox11"), TextBox).Text & Chr(9) & CType(item.Cells(11).FindControl("Textbox12"), TextBox).Text & Chr(9) & CType(item.Cells(12).FindControl("Textbox13"), TextBox).Text & Chr(9) & CType(item.Cells(13).FindControl("Textbox14"), TextBox).Text & Chr(9) & CType(item.Cells(14).FindControl("Textbox15"), TextBox).Text & Chr(13) & Chr(10)
            resp.Write(colRow)
        Next item

but getting an error :

Object reference not set to an instance of an object.


Private Sub ExportBut_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles ExportBut.Click

        Dim resp As HttpResponse

        resp = Page.Response

        resp.ContentType = "application/download"

        resp.AppendHeader("Content-Disposition", "attachment;filename=GLdata.xls")

        Dim colHeaders As String

        Dim myCol As DataGridColumn

        Dim i As Integer

        For i = 0 To 16

            resp.Write(Chr(13) & Chr(10))

        Next

        For Each myCol In DataGrid1.Columns

            colHeaders = colHeaders & myCol.HeaderText & Chr(9)
        Next

        If colHeaders.Length > 0 Then

            colHeaders = colHeaders.Substring(0, colHeaders.LastIndexOf(Chr(9)))

        End If

        colHeaders = colHeaders & Chr(13) & Chr(10)

        resp.Write(colHeaders)

        Dim colRow As String

        Dim item As DataGridItem

        For Each item In DataGrid1.Items
            colRow = item.Cells(0).Text & Chr(9) & item.Cells(1).Text & Chr(9) & item.Cells(2).Text & Chr(9) & item.Cells(3).Text & Chr(9) & item.Cells(4).Text & Chr(9) & item.Cells(5).Text & Chr(9) & item.Cells(6).Text & Chr(9) & item.Cells(7).Text & Chr(9) & item.Cells(8).Text & Chr(9) & item.Cells(9).Text & Chr(9) & item.Cells(10).Text & Chr(9) & item.Cells(11).Text & Chr(9) & item.Cells(12).Text & Chr(9) & item.Cells(13).Text & Chr(9) & item.Cells(14).Text & Chr(13) & Chr(10)
            resp.Write(colRow)
        Next item

        resp.End()

    End Sub