How can I tell if a domain name is free or not?

[multimediocrity]

I would like to put an application on my web page so users can type in a web address and know whether or not it is free. How do I build this, or where can I get a prebuilt script?

Thanks!
- Multi

[Declan1991]

Whois?

[multimediocrity]

Thanks, but I'm looking for an application that I can add to my site so people can look up domains from MY site. Does domaintools have the script somewhere?

[astupidname]

Is this what you are looking for? :
http://www.pcnames.com/webmaster/

[multimediocrity]

Yes! Thanks a lot! This is good enough and will suffice for my purposes.
Do you know of any others? Is there any way I could generate my own code?

[A1ien51]

If you could code your own, it is not going to be done with JavaScript, ould require a serverside language.

Eric

[multimediocrity]

That's true. I mistakenly added it to the JS thread, not PHP. I'll post it over there.

Thanks!