Error when committing the row to the original data store

Hi all,

I am working on a project involving Datagrid with an extended feature of
combo box

i am trying to stop the occurance of duplicate ID's
i want to trap the message "Error when committing the row to the original
data store"
i would like to display my own message box and cancel the row that is being
added.

could anyone please help me out

Thanks and Regards,
Sanjeev K. B