iframe自动高度

<script>
    //设置iframe自动高度
    function setIframe(id){
        var fn = function(){
            try{
                var iframe = typeof id=='string'?document.getElementById(id):id;
                var height = iframe.contentWindow.document.body.scrollHeight;
                iframe.height = height;
            }catch (ex){};
        };
        setInterval(fn,200);
    }
    setIframe('myIframe');
</script>