js dom元素加载完成执行

//dom ready执行
    function ready(fn){
        if(document.addEventListener){
            document.addEventListener('DOMContentLoaded',function(){
                document.removeEventListener('DOMContentLoaded',arguments.callee);
                fn();
            });
        }else if(document.attachEvent){
            document.attachEvent('onreadystatechange',function(){
                if(document.readystate=='complete'){
                    document.dispatchEvent('onreadystatechange',arguments.callee);
                    fn();
                }
            })
        }
    }