function showInfoWindow(marker) {


     var infoWindow = new google.maps.InfoWindow({
    content: (marker.title
      + '<br><img id="thumbnail" src = "img/'
      + marker.title.toLowerCase()
      + '.jpg"><br>'
      + '<ul>'
      + '<li id="infoWindowStart">Start from here</li>'
      + '<li id="infoWindowEnd">End here</li>'
      + '</ul>'
      )

  });

      infoWindow.open(map, marker);

   // then try to add a listener to the newly-created "infoWindowStart"
       document.getElementById("infoWindowStart").addEventListener("click",function(){
  console.log("We're going from here")
 });


}