security problem

my client wants a website to be viewable on only specific PCs. This is ridiculous I know but is it possible in any way??? Am tooooo confused. How can I do it

By PC do you mean certain IP addresses, certain operating systems, certain browsers?

Regardless though, you'll have to do this is a server-side script (PHP, ASP, etc.). Figure out which one you would like to use, or which one you have a available to use, and post it here. Then maybe a mod can move this thread into the appropriate forum for that language.

By the phrase "to be viewable on only specific PCs" I mean PCs which I will add into the list.
Any Server side lanuage will tell me the IP of a machine but look at the situation now.
a) users will be using dialups
b) users will be part of a LAN and of that network I want allow only specified PC to be able to login and browse. The only answer I cud find was MAC Addres of a machine.
If I ger MAC address I can enter into allowd database and only those will b able to browse. I will be using PHP and there is no way to find the mac address of a machine using PHP

See here.

While there are a few code snippets thrown around there, the main consensus is that you cannot find the mac address of a computer that the server is not directly connected to. Read the 9th post in that thread for more details.