function initCalloutbutton()
{
    var calloutBtnDiv = document.getElementById('calloutButton');
    map.controls[google.maps.ControlPosition.LEFT_BOTTOM].push(calloutBtnDiv)
    calloutBtnDiv.title = 'Click to toggle Callout Overlay';

    // Setup the click event listeners to toggle icon display
    calloutBtnDiv.addEventListener('click', function()
    {
        callout_showing = !callout_showing;
        // Determine which button image to show
        if (callout_showing)
        {
            pic = "images/btnDepressed_Callout.png"
            // It's nice when icons become visible that the messages have been refreshed.
            showCalloutLayer();
        }
        else
        {
            pic = "images/btnReady_Callout.png"
            hideCalloutLayer();
        }
        document.getElementById('calloutBtnImg').src = pic;

    });
  // Define the LatLng coordinates for the polygon's path.

    var triangleCoords =
    [{ lat: 33.84817790215087, lng: -117.9979705810547 },
{ lat: 33.80482636349161, lng: -118.02680969238283 },
{ lat: 33.80482636349161, lng: -117.97531127929689 },
{ lat: 33.84817790215087, lng: -117.9979705810547 }
    ];
  // Construct the polygon.
  region22 = new google.maps.Polygon({
    paths: triangleCoords,
    strokeColor: '#FF0000',
    strokeOpacity: 0.8,
    strokeWeight: 2,
    fillColor: '#FF0000',
    fillOpacity: 0.35
  });
}
var region22;
function showCalloutLayer()
{
    region22.setMap(map);
}
function hideCalloutLayer()
{
    region22.setMap(null);
}