Could not display a PHP file

Hello, I installed PHP5 and MySQL on my Linux machine running Apache web server. I could access this server from another computer by http://(hostname)/index.html Then I created a simple hello.php file: <html> .... <?php echo "hello" ?> .... </html> But when I tried http://(hostname)/hello.php from another computer, it just displayed this original text file, not "hello" in a browser. Is it an installation problem? How can I check it? Thanks, Joe ____________________________________________________ Sell on Yahoo! Auctions – no fees. Bid on great items. http://auctions.yahoo.com/