var messageId = 1;

function AddMessage () {

  var inputLine = document.getElementById('inputLine');
  var output = document.getElementById('Output');

  var newLine = document.createElement("p");
  newLine.setAttribute("class","chatOutputLine");

  var text = document.createTextNode(messageId + ": " + inputLine.value);

  output.appendChild( newLine.appendChild(text) );

  alert('Printed: ' + inputLine.value);
  inputLine.focus();
  inputLine.value = '';

  messageId++;
  return false;
} // AddMessage