Add JavaScript to the script element on the HTML5 page

Add in some needed variables for this session.

<script>

var localStream, localPeerConnection, remotePeerConnection;

var localVideo = document.getElementById("localVideo");
var remoteVideo = document.getElementById("remoteVideo");

var startButton = document.getElementById("startButton");
var callButton = document.getElementById("callButton");
var hangupButton = document.getElementById("hangupButton");
startButton.disabled = false;
callButton.disabled = true;
hangupButton.disabled = true;
startButton.onclick = start;
callButton.onclick = call;
hangupButton.onclick = hangup;

</script>