MooTools onHashChange Event

This is a simple script to add the onhashchange event to browsers that don't already support it.
Internet Explorer 8 and Firefox 3.6 have the 'onhashchange' event introduced.

Element.Events.hashchange = {
    onAdd: function(){
        var hash = self.location.hash;
        var hashchange = function(){
        if (hash == self.location.hash) return;
            else hash = self.location.hash;
            var value = (hash.indexOf('#') == 0 ? hash.substr(1) : hash);
            window.fireEvent('hashchange', value);
            document.fireEvent('hashchange', value);
        };
        if ('onhashchange' in window){
            window.onhashchange = hashchange;
        } else {
            hashchange.periodical(50);
        }
    }
};

window.addEvent('hashchange', function () { // do stuff });

https://github.com/mootools/mootools-core/blob/master/Source/Element/Element.Event.js#L141

http://caniuse.com/hashchange

hashchange: 1, popstate: 2, // history