获取URL中的参数

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