Edit box onkeypress event

I have an edit box control that is in the same panel as a link

I have SSJS code on the link that works fine (via a partial refresh of computed field on the same control but in a hidden panel)

If I put exactly the same code in the onkeypress event of the edit box (with the same partial refresh settings) (and trap for only the enter key via the client side code), I get an error saying “Problem submitting form…”

What am I missing? I have no validation on my edit box

Thanks

Mike