[PHP] php.net's index.php

[DrWebPat]

I was wondering what I would have to do in order to have index.php load up 
automatcially when someone went to my domain.  IE if they go to 
www.mydomain.com and I have index.html or index.htm there then those pages 
get loaded first.  How could I do it so index.php, index.php3, index.phtml 
were default as well?

Thanks,
Pat