A Class question

Hello Everyone, I have a very basic question, if i'm posting to the wrong place sorry. I'm learning PHP and Object Oriented Programing, and have build a class to add error messages into a error log file. The thing is can i load the class and after it use it on another class ? this is not like inherd My example code: File * index.php * <?php> include("error_class_php"); include("mysql_class_php"); echo "Acessing Mysql<br>"; $MY_ERROR = new error_class( "/home/logs" ); $MY_MYSQL = new mysql_class(); $MY_MYSQL -> do_some_select( "mysqL_user", "mysql_password"); ?> The thing is can i safely use the $MY_ERROR class ? and how can i keep the path "/home/logs" that i passed into the $MY_ERROR class ??? and use it always when the class is invoqued THankx and sorry if this is a very basic question, but i'm trying to learn 2 things at the same time PHP (which is great) and Object Oriented logic Stay Happy ! Miguel Angelo