help with autoload

I have a project the someone else wrote and that I can't get to work. It uses a rather large library of classes that are not apparently getting loaded by the provided __autoload() function. I'm not very well versed in PHP and one of the first things I did was see if in fact the __autoload function was being called. I place some print statements in it and got no result. But I don't know if that is because it is not really calling that function or perhaps the print outs are out of scope and won't be catched by the browser, I don't know. thanks, PHP: 5.1 TOMCAT: 5.5 Windows XP