[PHP] Detect if user has changed form data

Is there an easy way to detect if a user has changed the values in the fields of an HTML form? I want to be able to check this during the onUnload event and warn the user that he/she has not clicked the "Save" button to save changes to the form fields. The only way I can see to do this is to

RE: [PHP] Detect if user has changed form data

PHPBeginner.com (Where PHP Begins) [EMAIL PROTECTED] www.phpbeginner.com -Original Message- From: Ide, Jim [mailto:[EMAIL PROTECTED]] Sent: Tuesday, March 13, 2001 10:15 PM To: '[EMAIL PROTECTED]' Subject: [PHP] Detect if user has changed form data Is there an easy way to detect