Summary Row in DataGrid

[Compkitty]

Below is my code, however it's not finding the value

    If e.Item.ItemType = ListItemType.Item Or _
       e.Item.ItemType = ListItemType.AlternatingItem Then
            AdventVal += Convert.ToSingle(DataBinder.Eval(e.Item.DataItem, "MVValue"))
        ElseIf e.Item.ItemType = ListItemType.Footer Then
            e.Item.Cells(1).Text = "<b>Total:</b> " & String.Format("{0:c}", Value)
        End If

Value is Double
MVValue is a textbox w/ in the datagrid.