Prompt Users to Save Changes

Want to be able to prompt users if they have unsaved data and they close out the browser? Unfortunately, I've yet to find a cross browser solution but in Internet Explorer and Firefox the onbeforeunload event gives you just that ability. The event will fire when a user closes the browser or when a user navigates to a different URL. Simply have the function assigned to the event return the string you wish to display to the users.

window.onbeforeunload = function() {
    if(window.event.clientX < 0 || window.event.clientY < 0)
        return "You have unsaved changes. Are you sure you wish to leave this page?";
}

The above code is setup to only work on the browser or tab close button. Remove the if statement if you want it to work when a user navigates away from the page.