I need to have a field on one of the pages on our site check domain names for availability. We are a reseller of stuff like that, so I have access to whatever APIs our provider offers, but I don't have to use theirs only, I can use something like the http://domaintools.com stuff.

My question is, what is involved in getting this to function, from step 0? (Step zero is having a configured zencart but not much past that)

Thanks in advance, get as technical as you'd like.

-Tim