File Under: JavaScript

JavaScript Event – Unload

This code was written based on a template by John Resig. The original can be found at John Resig’s addEvent function website.

The code, and the template, are referred to in Webmonkey’s JavaScript Events reference page. In this example, the onUnload event fires when the user leaves the page, either by closing the window/tab, clicking a link, hitting the back button, or otherwise navigating to a different page.

The Code




// addEvent function by John Resig:


function addEvent( obj, type, fn ) {

  if ( obj.attachEvent ) {

    obj['e'+type+fn] = fn;

    obj[type+fn] = function(){obj['e'+type+fn]( window.event );}

    obj.attachEvent( 'on'+type, obj[type+fn] );

  } else

    obj.addEventListener( type, fn, false );





<!-- HTML for example event goes here -->


// Script for example event goes here

addEvent(window, 'unload', function(event) {

	alert('The user left the page');





What it Looks Like

See this HTML page example of the unload event and return here to see the alert.