function contact_is_email_valid(email)
  {
    var reg1 = /(@.*@)|(\.\.)|(@\.)|(\.@)|(^\.)/; // not valid
    var reg2 = /^.+\@(\[?)[a-zA-Z0-9\-\.]+\.([a-zA-Z]{2,3}|[0-9]{1,3})(\]?)$/; // valid
    return (!reg1.test(email) && reg2.test(email));
  }

  function contact_send_message()
  {
    $('#contact_err_no_email').hide();
    $('#contact_err_email_invalid').hide();
    $('#contact_err_no_subject').hide();
    $('#contact_err_no_message').hide();
    $('#contact_err_no_captcha').hide();

    var email = $('#contact_email').val();
    var subject = $('#contact_subject').val();
    var captcha = $('#contact_captcha_user').val();
    var message = $('#contact_message').val();

    if( email == null || email == "" )
    {
      $('#contact_err_no_email').show();
      return;
    }
    if( !(contact_is_email_valid(email)))
    {
      $('#contact_err_email_invalid').show();
      return;
    }
    if( subject == null || subject == "")
    {
      $('#contact_err_no_subject').show();
      return;
    }
    if( captcha == null || captcha == "")
    {
      $('#contact_err_no_captcha').show();
      return;
    }
    if( message == null || message == "")
    {
      $('#contact_err_no_message').show();
      return;
    }
    document.forms.contact_form.submit();
  }