title: Add Answer to peerJS script
body: <p>I'm not good in english but i try explain my problem.
  I'm using PeerJS to make call audio between to users.
  And I use this example: <a href="http://cdn.peerjs.com/demo/videochat" rel="nofollow">http://cdn.peerjs.com/demo/videochat</a> and it's work.
  But I want add answer or not answer to user in this script. How I can do it?
  This is my script:</p>
  
  <pre><code>&lt;html&gt;
  &lt;head&gt;
    &lt;title&gt;PeerJS - Video chat example&lt;/title&gt;
    &lt;link rel="stylesheet" href="style.css"&gt;
    &lt;link href="http://netdna.bootstrapcdn.com/bootstrap/3.0.2/css/bootstrap.min.css" rel="stylesheet"&gt;
    &lt;script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8/jquery.min.js"&gt;&lt;/script&gt;
      &lt;script type="text/javascript" src="./jquery.confirm.js"&gt;&lt;/script&gt;
  
    &lt;script src="./peer.min.js"&gt;&lt;/script&gt;
    &lt;script&gt;
  
      // Compatibility shim
      navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia;
  
      // PeerJS object
      var peer = new Peer({ key: 'lwjd5qra8257b9', debug: 3});
  
      peer.on('open', function(){
        $('#my-id').text(peer.id);
      });
  
      // Receiving a call
      peer.on('call', function(call){
        // Answer the call automatically (instead of prompting user) for demo purposes
  
          //here is Ansswer
  
        call.answer(window.localStream);
        step3(call);
  
      });
      peer.on('error', function(err){
        alert(err.message);
        // Return to step 2 if error occurs
        step2();
      });
  
      // Click handlers setup
      $(function(){
        $('#make-call').click(function(){
          // Initiate a call!
          var call = peer.call($('#callto-id').val(), window.localStream);
  
          step3(call);
        });
  
        $('#end-call').click(function(){
          window.existingCall.close();
          step2();
        });
  
        // Retry if getUserMedia fails
        $('#step1-retry').click(function(){
          $('#step1-error').hide();
          step1();
        });
  
        // Get things started
        step1();
      });
  
      function step1 () {
        // Get audio/video stream
        navigator.getUserMedia({audio: true, video: false}, function(stream){
          // Set your video displays
          $('#my-video').prop('src', URL.createObjectURL(stream));
  
          window.localStream = stream;
          step2();
        }, function(){ $('#step1-error').show(); });
      }
  
      function step2 () {
        $('#step1, #step3').hide();
        $('#step2').show();
      }
  
      function step3 (call) {
        // Hang up on an existing call if present
        if (window.existingCall) {
          window.existingCall.close();
        }
  
        // Wait for stream on the call, then set peer video display
        call.on('stream', function(stream){
          $('#their-video').prop('src', URL.createObjectURL(stream));
        });
  
        // UI stuff
        window.existingCall = call;
        $('#their-id').text(call.peer);
        call.on('close', step2);
        $('#step1, #step2').hide();
        $('#step3').show();
      }
  
    &lt;/script&gt;
  
      &lt;style&gt;
      .pure-g {
          width: 350px;
          margin: auto;
      }
      .pure-u-1-3{
          width: 100%;
      }
      &lt;/style&gt;
  
  &lt;/head&gt;
  
  &lt;body&gt;
  
    &lt;div class="pure-g"&gt;
        &lt;!-- Video area --&gt;
        &lt;div class="pure-u-2-3" id="video-container" style='display: none'&gt;
          &lt;video id="their-video" autoplay&gt;&lt;/video&gt;
        &lt;/div&gt;
  
        &lt;!-- Steps --&gt;
        &lt;div class="pure-u-1-3"&gt;
          &lt;h2&gt;SMA Voice Chat&lt;/h2&gt;
  
          &lt;!-- Get local audio/video stream --&gt;
          &lt;div id="step1"&gt;
            &lt;p&gt;Please click `allow` on the top of the screen so we can access your webcam and microphone for calls.&lt;/p&gt;
            &lt;div id="step1-error"&gt;
              &lt;p&gt;Failed to access the webcam and microphone. Make sure to run this demo on an http server and click allow when asked for permission by the browser.&lt;/p&gt;
              &lt;a href="#" class="pure-button pure-button-error" id="step1-retry"&gt;Try again&lt;/a&gt;
            &lt;/div&gt;
          &lt;/div&gt;
  
          &lt;!-- Make calls to others --&gt;
          &lt;div id="step2"&gt;
            &lt;p&gt;Your id: &lt;span id="my-id"&gt;...&lt;/span&gt;&lt;/p&gt;
            &lt;p&gt;Share this id with others so they can call you.&lt;/p&gt;
            &lt;h3&gt;Make a call&lt;/h3&gt;
            &lt;div class="pure-form"&gt;
              &lt;input type="text" placeholder="Call user id..." id="callto-id"&gt;
              &lt;a href="#" class="pure-button pure-button-success" id="make-call"&gt;Call&lt;/a&gt;
            &lt;/div&gt;
          &lt;/div&gt;
  
          &lt;!-- Call in progress --&gt;
          &lt;div id="step3"&gt;
            &lt;p&gt;Currently in call with &lt;span id="their-id"&gt;...&lt;/span&gt;&lt;/p&gt;
            &lt;p&gt;&lt;a href="#" class="pure-button pure-button-error" id="end-call"&gt;End call&lt;/a&gt;&lt;/p&gt;
          &lt;/div&gt;
        &lt;/div&gt;
    &lt;/div&gt;
  
  &lt;script src="http://netdna.bootstrapcdn.com/bootstrap/3.0.2/js/bootstrap.min.js"&gt;&lt;/script&gt;
  &lt;script src="https://google-code-prettify.googlecode.com/svn/loader/run_prettify.js"&gt;&lt;/script&gt;
  
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>Any Idea?</p>