Js获取URL地址参数

function   getUrlParam(name){   
          var   reg   =   new   RegExp("(^|&)"+   name   +"=([^&]*)(&|$)");   
          var   r   =   window.location.search.substr(1).match(reg);   
          if   (r!=null)   return   unescape(r[2]);   return   null;   
      }   
    
  getUrlParam("id")   结果是3

  http://www.sohu.com/test.htm?id=3