function addPolygon(points) {
    var polygon = new google.maps.Polygon({
        paths: points,
        strokeColor: " #FFFFFF",
        strokeOpacity: 0.15,
        strokeWeight: 1.5,
        fillColor: "#99ff66",
        fillOpacity: 0.14
    });
    var tooltip = document.createElement('div');
    tooltip.innerHTML = "Alok";

    google.maps.event.addListener(polygon,'mouseover',function(){
        tooltip.style.visibility = 'visible';
    });
    google.maps.event.addListener(polygon,'mouseout',function(){
        tooltip.style.visibility = 'hidden';
    });
    polygon.setMap(map);
}

//Add a listener for the click event
google.maps.event.addListener('click', showArrays);
infoWindow = new google.maps.InfoWindow;

function showArrays(event) {

  var contentString = 'Content here';

  // Replace the info window's content and position.
  infoWindow.setContent(contentString);
  infoWindow.setPosition(event.latLng);

  infoWindow.open(map);
}

map.data.addListener('mouseover', mouseOverDataItem);
map.data.addListener('mouseout', mouseOutOfDataItem));

function mouseOverDataItem(mouseEvent) {
  const titleText = mouseEvent.feature.getProperty('propContainingTooltipText');

  if (infoText) {
    map.getDiv().setAttribute('title', infoText);
  }
}

function mouseOutOfDataItem(mouseEvent) {
  map.getDiv().removeAttribute('title');
}