>ok, thank you for apply me first.
>
>But i also find the special problem. I have a dategridview and 3 fields (DataGridViewComboBoxColumn, DataGridViewComboBoxColumn , DataGridViewTextBoxColumn)
>Include currency master and currency exchange rate 2 table.
>for example, record. Currid currid2 exrate
> -------------------------------------------------------------
> USD HKD 7.8
> HKD RMB
>
>1. How to use your code to check if currid again entry USD is ok , but entry USD , HKD pop error duplicate.

Sorry, I'm still not clear on what would be regarded as a duplicate. I think you are saying that USD/HKD is OK but USD/USD is not - i.e. Currid and currid2 cannot be the same? Can you just confirm that please.


>2. Why use DataGridViewComboBoxColumn control, i can't use e.FormattedValue in dg.CellValidating to checking,
> even i select the HKD , then i set break point to see, it also e.FormattedValue =" " .
> How to check empty in dg.CellValidating method.
>
>
>Thank you ~~~