In an application I'm writing in PHP, a user will fill out one of many forms. Depending on what he put in those form fields, he may get an error (such as 'Subject must be more than 2 characters, please go back.'), however, when I hit the back button, all the fields are erased or go back to their initial value.

I'm using IE to develop this, and it just started happening recently. No other webpages do this, so I was wondering if there's something I did to cause it to reset the form information.

If seeing HTML source code would help, let me know. Thanks in advance.