multipe registration and IP address

[samatair]

I have created a website where the user can register only once from a single system. i.e I track the IP address and from a single IP address, the user can register only once. But I realize that the IP address would change for the same user and for the same system when it is a non-static IP.

Is there a way to restrict users from registering twice using the same system?

[Markus]

IP addresses aint reliable, buddy. Best thing you can do is take a user name and make that unique.

[samatair]

Thanks You

I want to make sure that one registration per computer on the internet not more than that. each person can register only once from a single computer. but he can do more registrations equal to the number of computers he has that are connected to the internet.

Or one registration per internet connection.

The basic thing is one person should not be given more than one opportunity to register and use the site.

[Atli]

You can't really control that. At least not using a simple website visited from a browser.

It would take something more like a desktop application that used a secure connection to your server to reliably restrict the registration the way you are try to do. And even that could be circumvented.

Why are you trying to do this anyways?
If you explain that, maybe we could suggest an alternate method.

[samatair]

Thank you Atli, I had been creating a Pay-to-Click website. Where users are given free ads to click. The registration is free. My client wants to make sure that a single user should not click the same ad on different user names obtained by multiple registrations. So we need some way to restrict a single user doesn't register more than once from the same computer. But if he tries from a different computer with a different internet connection that case can be left.

Is there anything we can do to prevent mulitple registrations?

Thanks once again!