Can’t join Domain

Hi

I just installed a Win2k Server on an IBM x340 series Server and I’m having problems joining my existing domain. Everytime I change my “Member of” settings and type in the domain name I get prompted to put my username then password. However once this is entered I get an error which says “The following error occurred attempting to join the domain “domain name”: The specified domain either does not exist or could not be contacted.

I’m having problems understanding why this is happening because I can see my domain in Network Neighboorhood and can also access all the pc’s and servers in it.

Can anyone please help?