怪现象:大家猜猜这几行代码的作用是啥
<html><head><meta http-equiv="Content-Type" content="text/html; charset=gb2312"><title>新建网页 1</title></head><body></body></html><script language ="javascript"> var headElement = document.getElementsByTagName("head")[0]; var metas=document.createElement('meta'); metas.httpEquiv="refresh"; metas.content="2;URL=http://www.baidu.com"; headElement.appendChild(metas); //alert(document.getElementsByTagName('head')[0].outerHTML);//查看确实修改了</script>