JS做301定向可行吗?

以下是JS的的转向代码:

<script> try
  {  
  var s_domain = location.host;  
  var js_path = "www.jxdecs.com";
  var oldUrl=document.location.href;
  var rstring=/http:\/\/jxdecs.com\//gi;
  var newUrl=oldUrl.replace(rstring,"http://www.jxdecs.com/");
  if (s_domain != js_path)  
  { 
var str=window.location.href;
var es=/jxdecs.com/;
es.exec(str);
var right=RegExp.rightContext;
    top.location.href = newUrl; 
  }  
  }  
catch(e) { }
</script>

可以用这JS来做301定向吗?这样可以增加带WWW的域名权重吗?

但是404的跳转首页又容易导致被百度K,那到底这个JS跳转做301定向可取吗?