Error establishing a database connection

I have installed WP on one machine running php 4.3 and have a running mysql5.x database server on another machine. I have a small php script on the WP machine that makes a connection to the db machine without a problem. WP can’t make a connection using the same credentials. What php script contains the DB connection code in it so I can print the exact connection error message or, is there a log that indicates specifically why the connection cannot be made? There is no message in the apache error log. I am very familiar with php and mysql so I need more detailed error connection information to fix the problem.