I have a peculiar problem ! I have written a PHP code which based on session tracking. Basically, The PHP code is for, if a user open an IE when he/she log in and after successful, he/she never log in from the same computer using IE till log out. But whenever I try there is a session error shown in IE. IE version is 6. After work around I got there r some bugs in IE6 for session tracking/errors. I got an alternative way. If I use Firefox or IE7 or upgrade the SP2 to SP3 the problem is solved. I have more or less 250 users, so it is not possible to provide the alternative solution to all users. Because, maximum users r using Windows XP SP2 with IE6. I am looking for a solution, please help me.