Google 地图 API v3 验证地点

Google Maps API v3 validate place

是否可以验证地点是否存在?在我下面的示例中,当您填写 "wkjdbvkwe" 之类的内容作为目的地时,它什么都不做。我想显示一些错误消息,但不知道如何验证 if destination =! real place.

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('txtDestination'));
        directionsDisplay = new google.maps.DirectionsRenderer({ 'draggable': true });
    });

    function GetRoute() {
        //*********DIRECTIONS**********************//
        source = "Čadca, Slovensko";
        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 dvDistance = document.getElementById("distance");
                dvDistance.innerHTML = "";
                dvDistance.innerHTML += distance;

            } else {
                alert("Nie je možné vypočítať vzdialenosť");
            }
        });
    }
<script src="http://maps.googleapis.com/maps/api/js?sensor=false&libraries=places.js"></script>

Destination: <input type="text" id="txtDestination" onblur="GetRoute()"  />
<br/>
<span id="distance"></span>

谢谢!

if (status == google.maps.DirectionsStatus.OK)

添加一个 else
 if (status == google.maps.DirectionsStatus.OK) {
            directionsDisplay.setDirections(response);
 } else {
    alert("Can't create directions:" + status);
 }