login problem

Hi, I am facing one problem.i previously mailed ,but there is no response,its running out of time.i want to implement that logic as soon as possible.This is my problem We are developing an online software for displaying ads in big mall.I want to restrict only one user can login to his own account at that particular time.suppose "users1" created a new user "users2" for another user.If "user1" login to the "users2" account and at that same time i want to restrict "user2 " for log in to his account.i want at a time only one user can access his account.I am waiting reponse from u A.suresh --------------------------------- Yahoo! India Answers: Share what you know. Learn something new Click here Catch all the FIFA World Cup 2006 action on Yahoo! India Click here