Hi All, my web application use a trick to detect when the browser is been closing from the "X" button. "onunload" event is handled by a function: function CleanUpSession() { if (window.event.clientX < 0) { // do cleanup } } This works well with IE6. Unfortunatly, the IE7 browser return always positive clientX value even if the mouse is out of client area. This means that the trick doesn't work in IE7. How can I solve this??? Thanks, Gianluca