var allowCaptchaRefresh = true;

function sendData() {
  $('f_email').disabled = true;
  $('f_captcha').disabled = true;
  $('su_button').disabled = true;

  allowCaptchaRefresh = false;

  new Ajax.Request('lostpwd.ajax.jsp', {
    method:'post',
    parameters: {
      f_email: $('f_email').value,
      f_captcha: $('f_captcha').value
    },
    onSuccess: function(transport) {
       eval(transport.responseText);

    }
  });
}

function captchaRefresh() {
  if (allowCaptchaRefresh) {
    d = new Date;
    $('captchaimage').src = '../../jsp/captcha.jsp?t=' + d.getTime();
    $('f_captcha').value = '';
    $('f_captcha').focus();
  }
}