How to Disable a Data Grid Column button from Code Behind

Public Sub DisableButton()

For totalrow = 0 To dgWelStatus.Items.Count - 1

If (CType(dgWelStatus.Items(totalrow).FindControl("lblStatusid"), Label).Text) = "790" Or (CType(dgWelStatus.Items(totalrow).FindControl("lblStatusid"), Label).Text) = "795" Or (CType(dgWelStatus.Items(totalrow).FindControl("lblStatusid"), Label).Text) = "797" Then

                    CType(dgWelStatus.Items(totalrow).FindControl("BtnAr_no"), Button).Enabled = False

                End If

            Next

End Sub