判断路径是否有想要的参数 和设置cookie以及获取cookie

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

function setCookie(name, value, day, path, domain)
{
    day = day || 30;
    path = path || '/';
    var str = name + '=' + value + '; ';
    if(day) str += 'expires=' + new Date(Date.now() + day * 24 * 3600 * 1000).toGMTString() + '; ';
    if(path) str += 'path=' + path + '; ';
    if(domain) str += 'domain=' + domain;
    document.cookie = str;
}
function getCookie(name){
    var arr,reg=new RegExp("(^| )"+name+"=([^;]*)(;|$)");
    if(arr=document.cookie.match(reg))
        return unescape(arr[2]);
    else
        return null;
}