function displayCN() {
  document.getElementById('sn').style.display = 'none';
  document.getElementById('cn').style.display = '';
  document.getElementById('result_text').innerHTML = '';
}

function displaySN() {
  document.getElementById('sn').style.display = '';
  document.getElementById('cn').style.display = 'none';
  document.getElementById('result_text').innerHTML = '';
}

var ac = new AjaxClient();

var textOnSuccess = "";
var textOnError   = "";

function subscribe(text, textos, textoe) {
  var email = document.getElementById('sn_email').value;
  if(email != '') { 
    textOnSuccess = textos;
    textOnError   = textoe;
    var url = "newsletter.php?email=" + email + "&action=subscribe";
    ac.sendRequest(url, onSubscribed);
  } else alert(text);
}

function onSubscribed() {
  if(!ac.isReady()) return;
  document.getElementById('result_text').innerHTML = (ac.getResponseText() == 1) ? textOnSuccess : textOnError;
  document.getElementById('sn_email').value = "";
}

function cancel(text, textos, textoe) {
  var email = document.getElementById('cn_email').value;
  if(email != '') { 
    textOnSuccess = textos;
    textOnError   = textoe;
    var url = "newsletter.php?email=" + email + "&action=cancel";
    ac.sendRequest(url, onCancelled);
  } else alert(text);
}

function onCancelled() {
  if(!ac.isReady()) return;
  document.getElementById('result_text').innerHTML = (ac.getResponseText() == 1) ? textOnSuccess : textOnError;
  document.getElementById('cn_email').value = "";
}