How to make single Selection of Radio Button in a Grid View using VB.net

Some time its happens in a Gridview have a column with more radio buttons but it do not select a single selection of a radio button. It selects all the radio buttons as you select it. For get Rid from this Problem. Given Below function can help you:

Protected Sub RdAdd_CheckedChanged(ByVal sender As Object, ByVal e As System.EventArgs)

        Dim dr As GridViewRow

        Dim oldRow As RadioButton = GdvAdd.FindControl("rdadd")

        Dim count = 0

        'TextBox3667.Text = Request.Form("RDI")

        For Each dr In GdvAdd.Rows

            oldRow = CType(GdvAdd.Rows(count).FindControl("rdadd"), RadioButton)

            oldRow.Checked = False

            count += 1

        Next

        'ADD Old Value

        Dim NewRow As RadioButton = sender

        Dim row As GridViewRow = NewRow.NamingContainer

        NewRow.FindControl("rdadd")

        NewRow.Checked = True

    End Sub