Forms Validation

I could use some coder help.

I have a page manager panel that displays a view with exposed filters for Location/Proximity and displays results of stores, along with a gmap for all resulting locations.

This works like a champ. The problem is I need to validate the results to make sure a zip code is entered, otherwise the result set is every store and the map takes a lot of time and resources to render.

I am trying to validate on the submit button, but it appears that the submit button is validated even before it is clicked.