Instaling PHP in windows with Apache

Dear All I've installed Apache Server in my PC (windows9*) and it is running ok. I get an answer when I ping my own machine and I can see apache's default homepage. I've made the changes necessary in the httpd.conf file. I've configured my php.ini and copied the dlls to the windows directory. Still when I try to see the result of a simple code such as the one below on a browser... <html> <head></head> <body> <? echo("hello world!") ?> </body> </html> ...I get black page Has anyone gone through the same problem? Can anyone point out a solution? Thank you! Margarida