PowerForms is a tool for extending your HTML pages with client-side input validation without requiring programming. Regular expressions can be defined in XML- (or Perl-) syntax and bound to input fields ensuring that clients can only enter and submit data that complies with the regular expression. PowerForms compiles the regular expressions to efficient JavaScript, exploiting only the subset of JavaScript that is known to run on all (normal) browsers. PowerForms can also cope with field interdependency where it can automatically deselect illegal radio buttons and checkboxes, and deselect and filter illegal select fields.
