The biggest problem with this is that you are poorly implementing a solution for your website and opening up a big hole on your own server.
Actually this is a bigger problem, usually with ASP scripts like this you can only view files in the current DIR. With the one above you can view the entire drive. This is a big problem for sites such as BRINKSTER.COM who support ASP scripts. They allow users to create an ASP bases home page and with a script like this you can access all other accounts/folders/files that are on the server's HD.