Problem detecting HTTPS connection

Hi all, I've been struggling to detect HTTPS connection for a shopping cart. I've used $_SERVER['SERVER_PORT'] to check for 443 and it kept on showing up as 80. Does anyone have any idea why this is happening? Is it the server config? I've called the server administrator and he said that it is running through port 443 for https connections. Here's an output of $_SERVER['SERVER_PORT'] on the site that I'm working on: https://www.axentonline.com.au/port_test.php http://www.axentonline.com.au/port_test.php Both the above are showing server_port as 80. Please assist. Thanks. PHPInfo: ------- Apache-AdvancedExtranetServer/2.0.50 Mandrakelinux/7.2.101mdk mod_ssl/2.0.50 OpenSSL/0.9.7d PHP/4.3.8 -- Wee Keat Chin Protocol Networks p: 1300 131 932 e: weekeat@pn.com.au h: www.pn.com.au