       }
            }

            //--- only called for "track" typed messages
            evtSource.addEventListener( "track", function(event) {
              console.log(event);
              document.getElementById("type").textContent = "track";
              if (event.data.length >0) {
                document.getElementById("data").textContent = event.data;
              }
            });
        </script>
</head>

<body unload="evtSource.close();">
<h1>Race Track Example</h1>

<div id="type">no type