This was written as a quick example to a friend as to how php can validate forms without javascript. In addition it demonstrates how a hidden input attribute can inform php whether or not the form has been filled out yet. All in all this is not that impressive. Of course, as an aid to someone writing a similar php page, it had to be kept simple and short, to be easy to understand and build on.

A possible extension would be to have errors not be concatinated and displayed all in one area, but rather to be displayed next to the item where the error occured. This could be accomplished by using multiple error variables in the form, or by using an associative array to the same ends.