How do I specify my own “File not found”, “Access forbidden”, and “Internal error” page?

This feature allows you to bring up a page of server information, including Aliases, the Server Administration contact email address, and general information about your website. Here you can see whether or not SSL is available and if Server Side Includes are enabled. There are three empty fields that allow you to specify customizable message files for specify error page. To use the error message feature, simply FTP (upload) html documents to our servers that have the error message you would like to display. Then, type the file names into the provided fields.