js获取地址栏的参数

 //获取url参数
    window.getParam = function(url, id) {
      url = url+ "";
      var regstr = "/(\\?|\\&)" + id + "=([^\\&]+)/";
      var reg = eval(regstr);
      var result = url.match(reg);

      if (result && result[2]) {
        return result[2];
      }else{
        return ''
      }
    }