I've got a really simple file with two fields: SysID and Manufacturer. There are two keys, both unique to each field.
I've got a browse with EIP for just the one field: Manufacturer, and it's great if you find a spelling error. But if the user changes a mispelled word, like Porche to Porsche, and there was already a Porsche in another record, it gives an error 40 (duplicate key), but it does so on the server (my app) and not the user's browser. Is there some way to intercept the message so it doesn't hang the system?