Add JavaScript to the script element on the HTML5 page

Add in the script element to the HTML5 document and add some needed variables for this session.

<script>

var sendChannel, receiveChannel;

var startButton = document.getElementById("startButton");
var sendButton = document.getElementById("sendButton");
var closeButton = document.getElementById("closeButton");
startButton.disabled = false;
sendButton.disabled = true;
closeButton.disabled = true;
startButton.onclick = createConnection;
sendButton.onclick = sendData;
closeButton.onclick = closeDataChannels;

</script>