get the closest streetview image within
          // 50 meters of the markers position
          streetViewService.getPanoramaByLocation(marker.position, radius, getStreetView);
          // Open the infowindow on the correct marker.
          infowindow.open(map, marker);
        }
      }

      // This function will loop through the markers array and display them all.
      function showListings() {
        var bounds = new google.maps.LatLngBounds();
        // Extend the boundaries of the map for each 