Google location autocomplete search box freeze when type? !

Hi,
I have strange problem, which not able to solve without help.
I'm building for school asp.net application. One part of web form contains Google Location input box, with dropdown autocomplete results. In previous version of my application the code works fine. But now, when I start upgrading application, and for Google Location just copy/paste the codes, it stopped working. Each time when try to type anything into search box, input control freeze, background gray, and gray exclamation mark.
Attaching print screen picture.

If someone has experience, I will be appriciate of sharing. Thanks in advance.

What I have tried:

<div>
     <script type="text/javascript" src="http://maps.googleapis.com/maps/api/js?sensor=false&libraries=places"></script>
            <script type="text/javascript">

        google.maps.event.addDomListener(window, 'load', function () {

            var places = new google.maps.places.Autocomplete(document.getElementById('txtPlaces'));

            google.maps.event.addListener(places, 'place_changed', function () {

                var place = places.getPlace();

                var address = place.formatted_address;

                var latitude = place.geometry.location.lat();

                var longitude = place.geometry.location.lng();

                var mesg = "Address: " + address;

                mesg += "\nLatitude: " + latitude;

                mesg += "\nLongitude: " + longitude;

                alert(mesg);

            });

        });

    </script>

    <span>Location:</span>

    <input type="text" id="txtPlaces" style="width: 250px" placeholder="Enter a location" />
    </div>

Tags: ASP.NET