<style>
/* Always set the map height explicitly to define the size of the div
 * element that contains the map. */
#map {
  height: 100%;
}
/* Optional: Makes the sample page fill the window. */
html, body {
  height: 100%;
  margin: 0;
  padding: 0;
}
#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;
}
</style>
<script>
  function initMap() {
  var map = new google.maps.Map(document.getElementById('map'), {
    zoom: 8,
    center: {lat: -34.397, lng: 150.644}
  });
  var geocoder = new google.maps.Geocoder();

  document.getElementById('submit').addEventListener('click', function() {
    geocodeAddress(geocoder, map);
  });
}

function geocodeAddress(geocoder, resultsMap) {
  var address = document.getElementById('address').value;
  geocoder.geocode({'address': address}, function(results, status) {
    if (status === 'OK') {
      resultsMap.setCenter(results[0].geometry.location);
      var marker = new google.maps.Marker({
        map: resultsMap,
        position: results[0].geometry.location
      });
    } else {
      alert('Geocode was not successful for the following reason: ' + status);
    }
  });
}
</script>