First of all you should try running a simple test script on your server. Something like...
<?
echo "PHP Working";
?>
save it and call it from the web browser.. if nothing appears then it is a configuration problem or if something does appear then it means that the other script you were running had an error and you have the "display_errors" option set to "off" in the php.ini file.
Try these suggestions then get back to us.
Option