I beg for help :-)

Hi, I wrote a few messages asking how to setup PHP in a iPlanet or Netscae Web Server environment. I tried with PWS and it did work. But I'm trying to set it up in iPlanet. What I've got is not too much. When the php3 file is called from the main page it seems to download it instead of executing it. It also opens the MS-DOS windows for php, but it does nothing. I'm newbie in this so I hope someone could help me. I don't understand why my sample page works with PWS but doesn't with iPlanet. What am I doing wrong??? What else do I need? Perhaps a gun for shooting myself??? :-)) Thank you all.