function reload_login_seccode() {
    $("login_captcha").value = "";
    load_seccode("login_seccode", "login_secimg", function() {
        $("login_captcha").focus();
    }); 
    return false;
}

function do_login(f) {
    var login_name = f.login_name.value;
    var login_password = f.login_password.value;
    var login_captcha = f.login_captcha.value;
    var err = "";

    if(trim(login_name) == "") {
        err += "请输入登入会员帐号\n";
        f.login_name.value = "";
    }
    if(trim(login_password) == "") {
        err += "请输入登入会员密码\n";
        f.login_password.value = "";
    }
    if(trim(login_captcha) == "") {
        err += "请输入验证码!\n"
        f.login_captcha.value = "";
    }
    if(err != "") 
        alert(err);
    else {
        /* do login */
        showLightbox("login_message_box", 410, 30, true);
        var data = "login_name=" + login_name + "&login_password=" + login_password + "&login_captcha=" + login_captcha + "&curl=" + f.curl.value + "&login_seccode=" + f.login_seccode.value;
        var long_login_timer = setTimeout('$("login_msg").innerHTML = "登入程序仍在进行中，请耐心等候 ...";', 3000);

        ajax_load("do_login.php", "post", data, function(res) {
            clearTimeout(long_login_timer);
            var ret = zretcode(res);
            if(ret.code < 0) {
                if(ret.msg.search(/认证码错误/) > 0)
                    reload_login_seccode(); 
                alert(ret.msg);
                hideLightbox();
            } else {
                $("login_msg").innerHTML = "成功登入！正在转向 ..."; 
                location.href = res; 
            }   
            return false;
        }); 

        return false;
 
    }

    return false;
}