function mail_ajax(mode)
{
    $("send_status").style.display = 'block';
    document.mail_form.mail_preview.disabled = true;
    document.mail_form.mail_post.disabled = true;
    var params = Form.serialize("mail_form");
    if (mode == "post") {
        params += "&mail_post=1";
    }
    else if (mode == "preview") {
        params += "&mail_preview=1";
    }

    new Ajax.Request("http://www.shinbitai.com/admin/mt/plugins/MailForm/mt-mail-form.cgi",
                     { method : "post",
                       parameters : params,
                       onComplete : displayMailResult,
                       onFailure : failureMailResult });
    return false;
}

function displayMailResult(obj)
{
    document.mail_form.mail_preview.disabled = false;
    document.mail_form.mail_post.disabled = false;
    $("send_status").style.display = 'none';
    $("ajax_mail").innerHTML = obj.responseText;
}

function failureMailResult(obj)
{
    alert('メールの処理が失敗しました。');
    document.mail_form.mail_preview.disabled = false;
    document.mail_form.mail_post.disabled = false;
    $("send_status").style.display = 'none';
}