Window beforeunload Event

 Description :
                       This event fires before page leave .You can also ask confirmation on page leave.

In JQuery Use this syntax to bind Beforeunload Event



$(window).bind("beforeunload",function(event) {
    if(hasChanged) return "You have unsaved changes";
});




And if You want to Perform some action on page leave and not want confirmation Dialog Box

$(window).bind("beforeunload",function(event) {

    if(hasChanged) alert('Hello');

         null;

});