control browser with <a href> tag

hi friends, i have two pages: list.php and update.php list.php will have a hyper link that when click on, it will open a new window for user to update info. once user clicks update button on update.php page, i want to close update.php and return to list.php. however if user doesn't click update button, i don't want user to go back to list.php. in other word, freeze up list.php until user closes or clicks update button on update.php. is this possible to do with php? thanks