更多可参考：

// 读 cookie 方法function getCookie(name){    var arr = document.cookie.match(new RegExp("(^| )"+name+"=([^;]*)(;|$)"));        if(arr != null)             return decodeURI(arr[2]);     return null;}// 写 cookie 方法function setCookie(name,value,expiredays){    if(!isNaN(expiredays)){        var date = new Date();        date.setDate(date.getDate() + expiredays);        //date.setTime(date.getTime() + expiredays * 24 * 3600 * 1000);        document.cookie = name + '=' + encodeURI(value) + ';expires=' + date.toGMTString();    } else {        document.cookie = name + '=' + encodeURI(value);    }}alert(getCookie("name"));setCookie('name','游客');setCookie('name','普通用户',7);