Google Maps Application Developing —— Search Address

<script type="text/javascript">
(function(){
    var map, geocoder, marker, infowindow;
 
    window.onload = function(){
         
        var mapOptions = {
            zoom:14,
            center:new google.maps.LatLng(39.9, 116.4),
            mapTypeId:google.maps.MapTypeId.ROADMAP
        };
 
        map = new google.maps.Map(document.getElementById('map'), mapOptions);
 
        var form = document.getElementById('addressForm');
 
            form.onsubmit = function(){
            var address = document.getElementById('address').value;
 
            getCoordinates(address);
 
            return false;
        }
    }
 
function getCoordinates(address){
    if(!geocoder){
        geocoder = new google.maps.Geocoder();
    }
 
    var geocoderRequest = {address:address}
         
    geocoder.geocode(geocoderRequest, function(results, status){
        if(status == google.maps.GeocoderStatus.OK){
            map.setCenter(results[0].geometry.location);
 
            if(!marker){
                marker = new google.maps.Marker({map:map});
            }
            marker.setPosition(results[0].geometry.location);
 
            if(!infowindow){
                infowindow = new google.maps.InfoWindow();
            }
 
            var content = '<strong>' + results[0].formatted_address + 
                    '</strong><br/>';
            content += '纬度: ' + results[0].geometry.location.lat() + '<br/>';
            content += '经度: ' + results[0].geometry.location.lng();
 
            infowindow.setContent(content);
 
            infowindow.open(map, marker);
        }
    });
}
})();