title: map routing is working but on change of source or destination it doesn't reflect
body: <p>I have shown nested map routing on google map..</p>
  
  <p><strong>At the first view it shows good routing on map, but we change point from dropdown then according to functionality it should get reflected on map..</strong></p>
  
  <p>my code snippet as follow:</p>
  
  <pre><code>&lt;style&gt;
  html,
  body,
  #map {
    height: 90%;
    width: 90%;
    margin: 0px;
    padding: 0px
  }
  .org{
      margin-left: 8%;    
      overflow: hidden;
      position: absolute;
      top: 10px;
      width: 92%;
  }
  .org_sel {
      float: left;
      margin-right: 30px;
      width: 12%;
  }
  
  .org_city{
    width: 200px; 
    height: 34px;
  }
  .dest_city{
    width: 200px; 
    height: 34px;
  }
  .dest_sel {
      float: left;
      margin-right: 30px;
      width: 12%;
  }
  &lt;/style&gt;
  &lt;html&gt; 
  &lt;head&gt;
     &lt;title&gt;Map Demo&lt;/title&gt;
  &lt;/head&gt; 
  &lt;div id="map"&gt;&lt;/div&gt;
  &lt;div class="org"&gt;
     &lt;div class="org_sel"&gt;
       &lt;select id="origin" class="org_city"&gt;
         &lt;option value="28.238897, 2.227514"&gt;Algeria&lt;/option&gt;
         &lt;option value="40.641176, -73.777796"&gt;New York&lt;/option&gt;
       &lt;/select&gt;
     &lt;/div&gt;
  
     &lt;div class="dest_sel"&gt;
       &lt;select id="destination" class="dest_city"&gt;
         &lt;option value="19.089681, 72.865486"&gt;Mumbai&lt;/option&gt;
         &lt;option value="21.090766, 79.054833"&gt;Nagpur&lt;/option&gt;
  
       &lt;/select&gt;
     &lt;/div&gt;
  
     &lt;div class="org_sel"&gt;
       &lt;select id="destination1" class="org_city"&gt;
       &lt;option value="39.882300, 116.289431"&gt;Beijing&lt;/option&gt;       
         &lt;option value="59.923152, 10.688673"&gt;Oslo&lt;/option&gt;
       &lt;/select&gt;
     &lt;/div&gt;
  
     &lt;div class="dest_sel"&gt;
       &lt;select id="destination2" class="dest_city"&gt;
         &lt;option value="59.367975, 18.115430"&gt;Stockholm&lt;/option&gt;
         &lt;option value="56.199034, 92.734745"&gt;Krasnoyarsk&lt;/option&gt;
       &lt;/select&gt;
     &lt;/div&gt;
   &lt;/div&gt;
  &lt;/html&gt;
  &lt;script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"&gt;&lt;/script&gt;
  &lt;script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyDgO1x-l4g_ofV7Q26EzJPA7tYDcKhpauQ&amp;libraries=places&amp;callback=initMap"&gt;&lt;/script&gt;
  
  &lt;script&gt;
  
  var cnt = 0;
  var locations = [];
  var flightPathCoordinates = [];
  
  function initMap(org, dest1, dest2, dest3) {
              map = new google.maps.Map(document.getElementById('map'), {
                zoom: 3,
                center: {lat: 28.615809, lng: 77.217683},
                mapTypeId: 'terrain'
              });
  
              if(cnt==0)
              {
                      flightPathCoordinates = [
                        {lat: 28.238897, lng: 2.227514},
                        {lat: 19.089681, lng: 72.865486}, 
                        {lat: 39.882300, lng: 116.289431},
                        {lat: 59.367975, lng: 18.115430}                  
                      ];
              }else
              {               
                     var org_arr = org.split(', ');
                     var dest_arr = dest1.split(', ');
                     var dest1_arr = dest2.split(', ');
                     var dest2_arr = dest3.split(', ');                            
  
                     flightPathCoordinates = [];
  
                     flightPathCoordinates = [
                          {lat: org_arr[0], lng: org_arr[1]}, 
                          {lat: dest_arr[0], lng: dest_arr[1]},
                          {lat: dest1_arr[0], lng: dest1_arr[1]},
                          {lat: dest2_arr[0], lng: dest2_arr[1]}
                     ];   
              }
  
              cnt = cnt + 1;        
  
              flightPath = new google.maps.Polyline({
                path: flightPathCoordinates,
                geodesic: true,
                strokeColor: '#FF0000',
                strokeOpacity: 1.0,
                strokeWeight: 2
              });
  
              console.log(flightPath); 
  
              flightPath.setMap(map);
  }
  
  google.maps.event.addDomListener(window, "load", initMap);
  
  jQuery(document).on('change','#origin',function (event) {
         var org = $('#origin').val(); 
         var dest = $('#destination').val();
         var dest1 = $('#destination1').val();
         var dest2 = $('#destination2').val();
  
         initMap(org, dest, dest1, dest2);
  });
  
  jQuery(document).on('change','#destination',function (event) {
         var org = $('#origin').val(); 
         var dest = $('#destination').val();
         var dest1 = $('#destination1').val();
         var dest2 = $('#destination2').val();
  
         initMap(org, dest, dest1, dest2);
  });
  
  jQuery(document).on('change','#destination1',function (event) {
         var org = $('#origin').val(); 
         var dest = $('#destination').val();
         var dest1 = $('#destination1').val();
         var dest2 = $('#destination2').val();
  
         initMap(org, dest, dest1, dest2);
  });
  
  jQuery(document).on('change','#destination2',function (event) {
         var org = $('#origin').val(); 
         var dest = $('#destination').val();
         var dest1 = $('#destination1').val();
         var dest2 = $('#destination2').val();
  
         initMap(org, dest, dest1, dest2);
  }); 
  
  &lt;/script&gt;
  </code></pre>
  
  <p>But when I change the points from dropdown then its not reflecting on map.. map gets disturbed..</p>