function validateFields()
{
  var elements = document.forms[0].elements;
  var emailPattern = /^[\w\.\-]+@([\w\-]+\.)+[a-zA-Z]+$/;

  for (var i = 0; i < elements.length; i++)
  {
    if (/(^| )checkRequired( |$)/.test(elements[i].className) && elements[i].value == "")
    {
      elements[i].focus();
      alert("Please fill out this field.");
      return false;
    }

    if (/(^| )checkEmail( |$)/.test(elements[i].className) && !emailPattern.test(elements[i].value))
    {
      elements[i].focus();
      alert("Please fill in a valid e-mail address.");
      return false;
    }
  }

  return true;
}