javascript - js设置cookie过期时间设置无效？

我用js设置cookie的时候expires总是设置不成功

window.onload = function(){
            var exp = new Date();
            exp.setTime(exp.getTime() + 30 * 24 * 60 * 60 * 1000);
            exp = exp.toGMTString();
            function setCookie(key, value, expires){
                var cookieStr = key + "=" + value;
                if(expires){
                    cookieStr += "; " + "max-age" + "=" + 1000;
                }
                // cookieStr += "; domain=baidu.com; path=/";
                document.cookie = cookieStr;
                console.log(document.cookie);
            }
            function getCookie(key){
                var cookieName = key + "=";
                var startIndex = document.cookie.indexOf(cookieName);
                var value = null;
                if(startIndex != -1){
                    var endIndex = document.cookie.indexOf(";", startIndex);
                    if(endIndex == -1){
                        endIndex = document.cookie.length;
                    }
                    value = document.cookie.substring(startIndex + cookieName.length, endIndex);
                }
                return value;
            }
            if(!getCookie("name")){
                document.getElementById("result").innerHTML = "Welcome!";
                setCookie("name", "xiaota", exp);
            }
            else{
                document.getElementById("result").innerHTML = "Welcome " + getCookie("name") + "!";
            }

调用setCookie函数的时候，传入时间，console.log打印的结果并没有expires，不知道怎么回事。