Check to See if Domain Is Available Script

Is there an easy way to check to see if a domain is available / not registered?

I am trying to connect to Internic to get the whois data, but it isn't working.

I am using .Net, but it doesn't matter the language, I can covert it over.

 

I checked for you
A php script
http://www.topdog.za.net/projects#topdog_whois_and_domain_check_script

 

Thanks Criv, but I found the error in my .Net code. I might create a webservice and allow others to hit it.