User login using cURL

Hi Support Team,
Myself Gurmeet, I am working on a project in which we are using a paid script called PHPPROADS we are integrating phpBB with this script. The requirement of client is to make a common login for both, So we have tried with cURL to login into phpBB forum. But it displays index page that we logged in only once if we hit any link or if page refresh, it shows that we are not logged in, for reference just hit this link to see the problem. http://www.i-swap.com.au/forum/mycurl.php.
Your prompt response will be appreciated.
Thanks,
Gurmeet