.so files?

Hello ... First of all sorry for my bad English . i am beginner with PHP core hacking , and i want to write my own extensions , i wrote my test extension and i compile the PHP code with it without any problem , (it's PHP 4.x) . my problem is i don't get the .so file after compile the source , so how i can get the .so file of my extension to use it ? --------------------------------- Yahoo! Messenger with Voice. Make PC-to-Phone Calls to the US (and 30+ countries) for 2¢/min or less.