主题：请教：怎样用SELECT CASE 写这段代码

Select Case e.Col.Name

     Case  "产品名称"

               if e.Row.IsNull("订单号") = True then

                  e.Cancel = True
               end if

 Case  "订购件数"

               if e.Row.IsNull("产品名称") = True then

                  e.Cancel = True
               end if

 Case  "到货日期"

               if e.Row.IsNull("订购件数") = True then

                  e.Cancel = True
               end if

end select