See a similar Categorized Q&A question at How do I detect and handle empty form fields?

(Use this link until vroom finishes fixing the other link syntax)

Now, I think you probably do not want to use a redirect. Send the form back, with the fields populated with what the user did enter. A co-worker of mine likes to put some kind of arrow graphic next to each field requiring the user's attention. You could also give empty fields a boldface label or use some other device to draw attention to the empty fields. If you don't detest javascript, you could even pop up a dialog telling the user what just happened, with instructions on how to fix it.

Good luck...

Russ
Brainbench 'Most Valuable Professional' for Perl