OOP problems with require/include

I have designed a class that handles all the SQL queries. I use this class to create objects throughout my scripts. However, I have other clases that rely on this class to work. Therefore, I "require" the code for the class and instantiate the object to use it. But there is a catch, PHP won't let you have nested Class declarations. Also, when I write a script that has this SQL class in it, but then intantiate an object that itself uses this class I get an error saying that I cannot redeclare a class. How do you experienced PHP programmers get around these limitations. Or am I just a sloppy OOP designer. I must admit I am new to this paradigm. Thanks in advance. _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. Share information about yourself, create your own public profile at http://profiles.msn.com.