function GetqueryString(name){
var reg = new RegExp("(^|&)"+ name +"=([^&]*)(&|$)");
var r = window.location.search.substr(1).match(reg);
if(r!=null)return unescape(r[2]); return null;
}
alert(GetqueryString("code")); //123
// http://www.abc.com/?code=123