动态加载JavaScript文件

函数封装

function loadScript(url,callback){    var script = document.createElement("script");    script.type = 'text/javascript';    if(script.readyState){//IE        script.onreadystatechange = function(){            if(script.readyState == 'loaded'             || script.readyState == 'complete'){                script.onreadystatechange = null;                callback();            }        }    }else{        script.onload = function(){            callback();        }    }    script.url = url;    document.getElementByTagName('head')[0].appendChild(script);}

使用案例

//加载文件loadScript('common.js',function(){    alert("common.js is loaded!");})//按照顺序加载文件loadScript('common.js',function(){    loadScript('core.js',function(){        loadScript('kernel.js',function(){            alert("All files are loaded!");        })    })})