function clearText(field) {

  if (field.defaultValue == field.value) field.value = '';
  else if (field.value == '') field.value = field.defaultValue;

}

function formCheck() {
   message = '';
   var firstName = document.JoinEmail.First.value;
   var lastName = document.JoinEmail.Last.value;
   var Email = document.JoinEmail.Email.value;

   if(firstName=='' || firstName=='First') {
     message = message + "- First name\n";
   }

   if(lastName=='' || lastName=='Last') {
     message = message + "- Last name\n";
   }

   if(!checkMail(Email)) 
   {
      message = message + "- Email\n";
   }

   if (message != '') {
     message = "Please submit:\n" + message;
     alert(message);
     return false;
   } else {
     sendMailingList(firstName, lastName, Email);
     return false;
   }
}

function checkMail(email) {
  ml = /.+@.+\..+/;

  if(!email.match(ml)) {
    return false;
  }
  return true;
}

function sendMailingList(first, last, email) {
  var time = (new Date()).getTime();
  var url = '/php/mailList.php?mode=send&md5=' + time;
  url = url + '&First=' +  first + '&Last=' +  last + '&Email=' +  email;

  var xmlhttp = getXmlhttp();

  xmlhttp.open('GET', url, true);

  xmlhttp.onreadystatechange = function() {
    if (xmlhttp.readyState == 4) {
      var str = xmlhttp.responseText;
      if(str) {
        xmlhttp.abort();
      }
    }
  }

  xmlhttp.send(null);

}