js獲取url中的參數

function GetQueryString(name) {
   var reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)","i");
   var r = window.location.search.substr(1).match(reg);
   if (r!=null) return (r[2]); return null;

}

alert(GetQueryString("參數名1"));
alert(GetQueryString("參數名2"));
alert(GetQueryString("參數名3"));