Help me .....Specified argument was out of the range of valid values.

[IndiraPriyaDarshini]

Hi ,
Am trying to sum the total in the footer if a gridview,
but am getting the error "Specified argument was out of the range of valid values.
Parameter name: index "..Its Printing one cell value in the footer..
But for the seond sum,it showing the error, the value is getting,

Help me pls..
Here is the ode snippent

Protected Sub GridView1_RowDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles GridView1.RowDataBound
        Dim sumPurchase As Double
        sumPurchase = 0
        sumPurchase = Ds.Tables(0).Compute("SUM(Purchase)", String.Empty).ToString
        'If e.Row.RowType = DataControlRowType.DataRow Then
        '    sumPurchase += Convert.ToDouble(DataBinder.Eval(e.Row.DataItem, "Purchase"))
        'Else
        If e.Row.RowType = DataControlRowType.Footer Then
            e.Row.Cells(0).Text = "Total"
            e.Row.Cells(2).Text = FormatCurrency(sumPurchase, 0)
 
            'e.Row.Cells(2).Text = sumPurchase
            'e.Row.Cells(3).HorizontalAlign = HorizontalAlign.Right
            'e.Row.Font.Bold = True
        End If
End Sub

[kenobewan]

Here is an article that may help:
Displaying Summary Information in the GridView's Footer