通過js代碼實現301跳轉的方法：
在對應的網頁文件中使用此JS代碼可實現301跳轉，比如將不帶www的域名跳轉到帶www的域名，代碼如下：
<script language=javascript> if (document.domain ==""yisu.com"") this.location = ""http://www.dadijd.cn"" + this.location.pathname + this.location.search; </script>
<script language=javascript>
if (document.domain ==""yisu.com"")
this.location = ""http://www.dadijd.cn"" + this.location.pathname + this.location.search;
</script>
