Prompt user when Page exits

Page

Page_Unload
Occurs when a server control is unloaded from memory, not closing a window

Or do you need to use a client event

How to close:
function Window.onunload ()
{
Alert ("Form closed!");
}
If you need to turn off prompts to the user before shutting down, and you want to close the browser Close button when the user clicks it, only the following methods are available to perform the event when exiting: function Window.onbeforeunload ()
{
if (event.clientx>document.body.clientwidth && event.clienty<0 | | event.altkey)
{
Window.event.returnvalue= "Are you sure you want to exit this page?";
}
}