scripts.js

  // Create a reference to firebase
  var messagesRef = new Firebase('https://hackeryou.firebaseio.com/chat');

  // C.R.E.A.M -  cache your elements
  var messageField = $('#messageInput');
  var nameField = $('#nameInput');
  var messageList = $('.messages');

  function addMessage(data) {
    var username = data.name || 'anonymous';
    var message = data.text;

    // Create an element
    var nameElement = $('<strong>').text(username);
    var messageElement = $('<li>').text(message).prepend(nameElement);

    // Add the message to the DOM
    messageList.append(messageElement);

    // Scroll to the bottom of the message list
    messageList[0].scrollTop = messageList[0].scrollHeight;
  }

  // Listen for the form submit
  $('.chat').on('submit',function(e) {

    // stop the form from submitting
    e.preventDefault();

    // create a message object
    var message = {
      name : nameField.val(),
      text : messageField.val()
    }

    // Save Data to firebase
    messagesRef.push(message);

    // clear message field
    messageField.val('');

  });

  // Add a callback that is triggered for each chat message
  // this is kind of like an Ajax request, but they come in via websockets
  // 10 of them will load on page load, and any future messages will as well
  messagesRef.limitToLast(10).on('child_added', function (snapshot) {
    // Get data from returned
    addMessage(snapshot.val());
  });