js 从 URL 获取查询参数:
function getParameterByName(name, url) {
if (!url) url = window.location.href;
name = name.replace(/[[]]/g, "\$&");
var regex = new RegExp("[?&]" + name + "(=([^&#]*)|&|#|$)"),
results = regex.exec(url);
if (!results) return null;
if (!results[2]) return '';
return decodeURIComponent(results[2].replace(/+/g, " "));
}