404Handler will trap those dreaded "404 Not Found" errors on your site and email you the details of each 404. You can choose to receive email on one of three levels: no mail, mail only if the 404 was generated by a link on your own site, or mail warnings
This programm automatically lists the values of POST, GET, FILES, COOKIE, SESSION and other defined variables as tree or list. It can be used for debugging all of your scripts.
The add_error page is used to report an error message. The person who reports the error has the option of reporting the error to one or more developers. The list_error.php files is used to list error reports in a certain order. The error reports are order