js 定时刷新验证码

function timeFunction() {
            document.getElementById("codeImg").src = "web/ValidateCode.aspx?i=" + Math.random();            
        }
        window.onload = function () {
            setInterval(timeFunction, 60000);
            var vUserName = getCookie('t_user');
            $("#txtUserName").val(vUserName);
        }