in mootools: calling a function after all events on an element is finished

i have this element to which various change events are applied how can i trigger my own function after all change events have occurred in mootools

a sample scenario is a drop down list

$('ddl').addEvent('change', function () { // some ajax call going on here and which i can't affect // as the page is gen开发者_如何学JAVAerated that way });

i now want to call my function right after the change event is done but adding another change event will not do as i believe the events are executed async

pass on a callback function through the onComplete of the ajax that you reference.

eg:

$("ddl").addEvents({
    change: function() {
        new Request({
           method: "get",
           url: "somefile.php",
           onComplete: function() {
               // run your next stuff from within here, referencing 
               // this.response.text or whatevever and call up another function.
           }
        }).send("action=checkuser&id="+this.get("value").trim());
    }
});

there's also the Chain class - http://mootools.net/docs/core/Class/Class.Extras#Chain but as you have async stuff going on, you really need the onComplete on the Request.