Google Maps Calculate Distance,Travel Duration, draw (plot) Route and display Directions between two locations

<script type="text/javascript" src="http://maps.googleapis.com/maps/api/js?sensor=false&amp;libraries=places"></script>
<script type="text/javascript">
        var source, destination;
        var directionsDisplay;
        var directionsService = new google.maps.DirectionsService();
        google.maps.event.addDomListener(window, 'load', function () {
            new google.maps.places.SearchBox(document.getElementById('txtSource'));
            new google.maps.places.SearchBox(document.getElementById('txtDestination'));
            directionsDisplay = new google.maps.DirectionsRenderer({ 'draggable': true });
        });

        function GetRoute() {
            var mumbai = new google.maps.LatLng(18.9750, 72.8258);
            var mapOptions = {
                zoom: 7,
                center: mumbai
            };
            map = new google.maps.Map(document.getElementById('dvMap'), mapOptions);
            directionsDisplay.setMap(map);
            directionsDisplay.setPanel(document.getElementById('dvPanel'));

            //*********DIRECTIONS AND ROUTE**********************//
            source = document.getElementById("txtSource").value;
            destination = document.getElementById("txtDestination").value;

            var request = {
                origin: source,
                destination: destination,
                travelMode: google.maps.TravelMode.DRIVING
            };
            directionsService.route(request, function (response, status) {
                if (status == google.maps.DirectionsStatus.OK) {
                    directionsDisplay.setDirections(response);
                }
            });

            //*********DISTANCE AND DURATION**********************//
            var service = new google.maps.DistanceMatrixService();
            service.getDistanceMatrix({
                origins: [source],
                destinations: [destination],
                travelMode: google.maps.TravelMode.DRIVING,
                unitSystem: google.maps.UnitSystem.METRIC,
                avoidHighways: false,
                avoidTolls: false
            }, function (response, status) {
                if (status == google.maps.DistanceMatrixStatus.OK && response.rows[0].elements[0].status != "ZERO_RESULTS") {
                    var distance = response.rows[0].elements[0].distance.text;
                    var duration = response.rows[0].elements[0].duration.text;
                    var dvDistance = document.getElementById("dvDistance");
                    dvDistance.innerHTML = "";
                    dvDistance.innerHTML += "Distance: " + distance + "<br />";
                    dvDistance.innerHTML += "Duration:" + duration;

                } else {
                    alert("Unable to find the distance via road.");
                }
            });
        }
    </script>
<body onLoad="GetRoute();">
<table border="0" cellpadding="0" cellspacing="3">
  <tbody>
    <tr>
      <td colspan="2"> Source:
        <input type="text" id="txtSource" value="Behror, Rajasthan, India" style="width: 250px" placeholder="Enter a query" autocomplete="off">
        &nbsp;&nbsp; Destination:
        <input type="text" id="txtDestination" value="Jaipur, Rajasthan, India" style="width: 250px" placeholder="Enter a query" autocomplete="off">
        <br>
        <br>
        <input type="button" value="Get Route" onclick="GetRoute()">
        <hr></td>
    </tr>
    <tr>
      <td colspan="2"><div id="dvDistance"> </div></td>
    </tr>
    <tr>
      <td><div id="dvMap" style="width: 500px; height: 500px"> </div></td>
      <td><div id="dvPanel" style="width: 500px; height: 500px;overflow-y:auto"> </div></td>
    </tr>
  </tbody>
</table>
</body>