Google maps -- pop up box - google-maps

Question

I have converted multiple shapefiles to KML using the Shp2kml2 software from Zonums Solutions. I have made a map with the KML layers (of which I have imported to google docs to get the url). As an example:
var ctaLayer = new google.maps.KmlLayer({
url: 'https://docs.google.com/uc?authuser=0&id=0B15UI5xGYTOadDlta2FoZ2pCc1E&export=download'
});
ctaLayer.setMap(map);
When I click on a polygon layer in google maps, the pop-up box opens. How can I make it so that when I click on a second polygon layer, the pop-up box that was selected earlier is automatically cleared and not shown anymore? (Because in my situation, the earlier pop-up box still shows up but I don't want this to happen because if the user selects multiple polygon layers, there would be too many pop-up box on the screen. I understand that the user can select X to delete the pop-up window but I would like to make it as user-friendly as possible).
In addition to the polygon layers, I have other point layers in the map. But when I try to click on a specific point, the pop-up information is that of the polygon which rests in the same place as the points.
My map is found in: http://userpages.flemingc.on.ca/~catam/collab.html

Answer 1

You could consider the following approach:
1)suppress a default info window:
var kmlOptions = {
suppressInfoWindows: true, // do not to display an info window when clicked
preserveViewport: false,
map: map
};
var layer = new google.maps.KmlLayer(url, kmlOptions);
2)register a shared instance of Info Window:
var infoWindow = new google.maps.InfoWindow();
var openInfoWindow = function (KMLevent) {
infoWindow.close();
infoWindow.setOptions(
{
content: KMLevent.featureData.infoWindowHtml,
position: KMLevent.latLng,
pixelOffset: KMLevent.pixelOffset
});
infoWindow.open(map);
};
google.maps.event.addListener(layer, "click", openInfoWindow);
Example