获取Url中某个参数值

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