从url后获取?之后的指定参数

function GetRequest() {
   var url = location.search; //获取url中"?"符后的字串
   var theRequest = new Object();
   if (url.indexOf("?") != -1) {
	  var str = url.substr(1);
	  strs = str.split("&");
	  for(var i = 0; i < strs.length; i ++) {
		 theRequest[strs[i].split("=")[0]]=(strs[i].split("=")[1]);
		  }
	   }
	   return theRequest;
	}

var res = GetRequest();
var wechatcode=res['code'];//抓取code后面的参数