Description: JavaScript is useful for a lot more than opening pop-ups. If you use HTML forms on your website, and want to make sure that your visitors submit valid data on those forms, you might want to consider using some regular expressions in JavaScript. Alejandro Gervasio explains how, with many excellent examples. Introduction If you ve ever programmed in Perl, or have had in your hands a UNIX system, then maybe you are pretty familiar with what regular expressions are.
