ON-ERROR vs ON-MESSAGE

Can anyone tell me what exactly is the difference between the ON-MESSAGE and ON-ERROR triggers in Forms? It seems unclear to me, because some messages have to be trapped in BOTH. For example, FRM-40352 last record queried is sometimes a message and sometimes an error. I want to suppress it and I have finally figured out that I have to suppress it in both ON-MESSAGE and ON-ERROR. Any information appreciated.

-------------------==== Posted via Deja News ====-----------------------
      http://www.dejanews.com/     Search, Read, Post to Usenet