[Zope] meaning error message

[Oai Luong]

My postgres database tables are setup to have unique index therefore no
duplicates are not allow.  If duplicate occur the db will return an
error.  Problem  is when i try to submit duplicate data to the db i get
an ugly error message.  Is there anyway i can output my own error
message for example "this data exist on the db already, please do not
submit again" ?  I don't want that error message because user's won't
understand what is talking about.


thanks.