anchor.diff:  <head>
     <title>Driving page</title>
     <script type='text/javascript'>
  -    var numberOfTests = 0;
  -    var currentId;
  +    var number_of_tests = 0;
  +    var current_id;
       var testing_window;
  +    var last_reported_id;
   
       function newTaskHandler() {
         if (this.readyState == this.DONE) {
  
positive.code:       var client = new XMLHttpRequest();
        function handleReady() {
          if (this.readyState == this.DONE) {
            getNextTask();
          }
        }
        client.onreadystatechange = handleReady;
        client.open('POST', '$reportPath/${browserId}?id=' + id);
        client.setRequestHeader('Content-type',
                                'application/x-www-form-urlencoded');
        client.send(msg);
  
negative.code:     }
  
      function run(url) {
        number_of_tests++;
        document.getElementById('number').innerHTML = number_of_tests;
        if (testing_window == undefined) {
          testing_window = window.open(url);
        } else {
  