ndow(this, largeInfowindow);
          });
          // Two event listeners - one for mouseover, one for mouseout,
          // to change the colors back and forth.
          marker.addListener('mouseover', function() {
            this.setIcon(highlightedIcon);
          });
          marker.addListener('mouseout', function() {
            this.setIcon(defaultIcon);
          });
        }

        document.getElementById('show-listings').addEventListener('click', showListings);
        document.getElement