A little JavaScript... Check out this link at DynamicDrive.com for info. You can't do this with PHP, since PHP is a server-side language and is parsed before it's ever sent to the browser, so you need to use client-side scripting... That's where the JavaScipt comes in. (Be aware though, that your users could experience ill-effects, from trying to use a form scripted like this with their JavaScripting turned off on their browsers, so just be cautious.