I'm trying get map with dropdown markers (every with infowindow). Multiple markers must start with HTML/CSS button. Infowindows should have different text. I can't build even with the same text in every infowindows. In console browser I see message: "SCRIPT445: Object doesn't support this action". I can't trigger Infowidow at all. My code /used from Google examples/ is below:
 <!DOCTYPE html>
        <html>
        <head>
        <meta charset="utf-8">
        <title>Marker animations with <code>setTimeout()</code></title>
        <style>
              html, body {
                height: 100%;
                margin: 0;
                padding: 0;
              }
              #map {
                height: 100%;
              }
        #floating-panel {
          position: absolute;
          top: 10px;
          left: 25%;
          z-index: 5;
          background-color: #fff;
          padding: 5px;
          border: 1px solid #999;
          text-align: center;
          font-family: 'Roboto','sans-serif';
          line-height: 30px;
          padding-left: 10px;
        }
              #floating-panel {
                margin-left: -52px;
              }
            </style>
          </head>
          <body>
            <div id="floating-panel">
              <button id="drop" onclick="drop()">Drop Markers</button>
             </div>
            <div id="map"></div>
            <script  async defer
        src=         "https://maps.googleapis.com/maps/api/jssigned_in=true&libraries=places&callback=initMap">
         </script>
        <script>
        var neighborhoods = [
          {lat: 52.511, lng: 13.447, name: "2007"},
          {lat: 52.549, lng: 13.422, name: "2008"}, 
          {lat: 52.497, lng: 13.396, name: "2009"},
          {lat: 52.517, lng: 13.394, name: "2010"}
        ];
        var markers = [];
        var map;
        function initMap() {
          map = new google.maps.Map(document.getElementById('map'), {
            zoom: 12,
            center: {lat: 52.520, lng: 13.410}
          });
        }
        function drop() {
          clearMarkers();
          for (var i = 0; i < neighborhoods.length; i++) {
            addMarkerWithTimeout(neighborhoods[i], i * 200);
          }
        }
        var contentString = '<div id="content">'+
              '<div id="siteNotice">'+
              '</div>'+
              '<h1 id="firstHeading" class="firstHeading">Uluru</h1>'+
              '<div id="bodyContent">'+
              '<p><b>Uluru</b>, also referred to as <b>Ayers Rock</b>, is a large ' +
              'sandstone rock formation in the southern part of the '+
              'Northern Territory, central Australia. It lies 335 km (208 mi) '+
              'south west of the nearest large town, Alice Springs; 450 km '+
              '(280 mi) by road. Kata Tjuta and Uluru are the two major '+
              'features of the Uluru - Kata Tjuta National Park. Uluru is '+
              'sacred to the Pitjantjatjara and Yankunytjatjara, the '+
              'Aboriginal people of the area. It has many springs, waterholes, '+
              'rock caves and ancient paintings. Uluru is listed as a World '+
              'Heritage Site.</p>'+
              '<p>Attribution: Uluru, <a            href="https://en.wikipedia.org/w/index.php?title=Uluru&oldid=297882194">'+
              'https://en.wikipedia.org/w/index.php?title=Uluru</a> '+
              '(last visited June 22, 2009).</p>'+
              '</div>'+
              '</div>';
        function addMarkerWithTimeout(position, timeout) {
          window.setTimeout(function() {
            var data = position;
            var marker = new google.maps.Marker({
              position: position,
              map: map,
              title: data.name,
              animation: google.maps.Animation.DROP
            });
             markers.push(marker);
            var infowindow = new google.maps.infowindowInfo({
                content: contentString,   
            });
            google.maps.event.addListener(marker, function() {
                if (this.getMap()) {
                  infowindow.open(this.getMap(), this);
                } else {
                  infowindow.close()
                }
              });
          }, timeout);
        }
        function clearMarkers() {
          for (var i = 0; i < markers.length; i++) {
            markers[i].setMap(null);
          }
          markers = [];
        }
        google.maps.event.addDomListener(window, 'load', initMap);
        </script>
          </body>
        </html
 
     
    