js Cookie设置和读取

//设置cookie
function setCookie (name, value, day) {
    //当设置的时间等于0时，不设置expires属性，cookie在浏览器关闭后删除
    var expires = day * 24 * 60 * 60 * 1000;
    var exp = new Date();
    exp.setTime(exp.getTime() + expires);
    document.cookie = name + "=" + value + ";expires=" + exp.toUTCString()+";path=/";
};
//删除cookie
 function delCookie (name) {
    setCookie(name, ' ', -1);
};
//获取cookie代码
function getCookie(name) {
    var arr;
    var reg = new RegExp("(^| )" + name + "=([^;]*)(;|$)");
    if (arr = document.cookie.match(reg)) {
        return arr[2];
    }
    else
        return null;
};