Problems connecting to remote mySQL server

I am trying to connect to a remote mySQL server through PHP but I get a mySQL error of "Unknown Database". I can connect to the remote mySQL server using the mysql command but not with PHP. 1. How can I debug what the problem is? 2. Do I need to specify the Port parameter in PHP? 3. Which mySQL error logs do I examine to help me out - the one on the local machine or on the remote machine? 4. And where is the mySQL error logs anyway? I tried other lists but no help there. I hope this list helps! Thanks all, Floyd Piedad