PHP has this functionality built in. There are several
excellent tutorials and of course the online documentation at
www.php.net.
http://www.phpbuilder.com/columns/mattias20000519.php3
http://www.informit.com/articles/article.asp?p=170279&rl=1
http://www.webkreator.com/php/configuration/foolproof-php-handling-2.html
http://www.php.net/errorfunc