<!DOCTYPE html>
<html>
  <head>
    <title>Installing Service Worker</title>
    <script type="text/javascript">
        var swsource = "/sw.js";
        if("serviceWorker" in navigator) {
          navigator.serviceWorker.register(swsource)
            .then(function(reg){
              console.log('SW scope: ', reg.scope);
            })
            .catch(function(err) {
              console.log('SW registration failed: ', err);
            });
        };
    </script>
  </head>
  <body>
    <!-- Instal