how to link login of punbb to applications

by reading the documentation for a start

hi
thanks for your reply.
I have used this way but i did not get the result what i am looking for.

Please help me

define('PUN_ROOT', './forums/');
require PUN_ROOT.'include/common.php';Once you've included common.php, you can access and utilize all of PunBB's global variables and functions. Typically, you will be most interested in the $pun_user array. This array holds information about the current user. Another interesting variable is the database object $db. How to use these variables in your own script is out of the scope of this document, but here's a small example showing you how to print a simple message greeting the current user on your website front page:

Hello <?php echo pun_htmlspecialchars($pun_user['username']); ?>!In addition to defining PUN_ROOT, you can define a number of other constants to alter the behaviour of PunBB when including common.php. The two most interesting of these constants are PUN_TURN_OFF_MAINT and PUN_QUIET_VISIT. If PUN_TURN_OFF_MAINT is defined when including common.php, PunBB will not exit and display the maintenance message if the forums are placed into maintenance mode. You generally don't want this message to appear on your website front page, so defining that constant is a good idea. The other constant, PUN_QUIET_VISIT, prevents PunBB from updating the current user's last visit data in the database so that a visit to the front page doesn't count as a visit in the forums. This is also desirable behaviour in most cases. It doesn't matter what value you set these constants to, but setting them to a value of 1 is probably a good idea. Example:

define('PUN_TURN_OFF_MAINT', 1);
define('PUN_QUIET_VISIT', 1);

Thanks in advance