code:

var s 代表url 的参数key 
//调用GetQueryString(s)
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;
}