load js dynamically

loadjs.js

function loadScript(path, callback) {
    var script = document.createElement('script');
    if (script.onreadystatechange) {
        script.onreadystatechange = function() {
            var st = script.readyState;
            if (st === 'loaded' || st === 'complete') {
                if(callback&&"function" === typeof callback){
                  callback();
                }
                script.onreadystatechange = null;
            }
        };
    } else {
        script.onload = function() {
            callback();
        };
    }
    script.src = path;
    document.getElementsByTagName('head')[0].appendChild(script);
}

//loadscript-mini.js
//window.loadscript=function(d,b){var a=document.createElement("script");a.onreadystatechange?a.onreadystatechange=function(){var c=a.readyState;if("loaded"===c||"complete"===c)b&&"function"===typeof b&&b(),a.onreadystatechange=null}:a.onload=function(){b()};a.src=d;document.getElementsByTagName("head")[0].appendChild(a)};