I hate typing, but I like writing code. A while ago I started to dread all the rote typing required to handle forms in PHP, and began looking for a Better Way. This article describes how I used PHP's regular expression functions to do most of the heavy lifting required to process forms properly, saving lots of typing and giving me time to do stuff I don't hate, such as writing code (and playing NetHack).
He sets it upJeff Cogswell, have had) to display the form, validate the input, and display the results of this validation (or a success message).
He takes a little bit different kind of method behind it than several form packages out there - he grabs the HTML output of the form with output buffering and does replaces on that with the previously entered values.