Hi all,
I am working on a parent-child form(built from wizard). On parent part, I have a field called SERIAL NO. This SERIAL NO. must NOT be duplicated. But when I add new record(for parent part), it automatically added as default. I used LOOKUP command to compare the field against the table. Even it found the matching record and give error message but still added new record.

What is the best way to handle duplicate error checking? Please help me if you have experience on this.

Thank you in advance.
Thanya.