Async.js

HTML

<script src="//cdnjs.cloudflare.com/ajax/libs/async/0.8.0/async.js"></script>
<h1>ascync.js</h1>

JavaScript

async.parallel([
    function(callback){
        setTimeout(function(){
            callback(null, 'one');
        }, 200);
    },
    function(callback){
        setTimeout(function(){
            callback(null, 'two');
        }, 100);
    },
     function(callback){
        setTimeout(function(){
            callback(null, 'three');
        }, 20);
    }
],
// optional callback
function(err, results){
    // the results array will equal ['one','two'] even though
    // the second function had a shorter timeout.
    if(err){
        console.log(err,results);
    }else{
        console.log(results);   
    }
});