Google Maps no carga

[vvarmo]

Hola amigos, por favor alguien me puede ayudar a cambiar el codigo que muestro aca de la apiV2 de google maps a la api v3? de verdad que me urge mucho!!

<script src="http://maps.google.com/maps?file=api&amp;v=2&amp;key={$GLOBALS.google_map s_API_key}" type="text/javascript"></script>
<script type="text/javascript">
var map;
{if $listing.location_is_set}
var zoom = 15;
{else}
var zoom = 7;
{/if}
{literal}
var latitude = {/literal}{$geoData.latitude}{literal};
var longitude = {/literal}{$geoData.longitude}{literal};

$(document).ready(function(){
if (GBrowserIsCompatible()) {
map = new GMap2(document.getElementById("map_canvas"));
map.setCenter(new GLatLng(latitude, longitude), zoom);
map.addControl(new GSmallMapControl());
map.addControl(new GMapTypeControl());
map.addControl(new GScaleControl());
map.addControl(new GOverviewMapControl());
var point = new GLatLng(latitude, longitude);
var marker = new GMarker(point, {draggable: true});
GEvent.addListener(marker, "dragstart", function() {
map.closeInfoWindow();
});
GEvent.addListener(marker, "dragend", function() {
$("#m_lat").val(marker.getLatLng().lat());
$("#m_lon").val(marker.getLatLng().lng());
});
GEvent.addListener(map, 'click', function(overlay, latlng) {
marker.setLatLng(latlng);
$("#m_lat").val(marker.getLatLng().lat());
$("#m_lon").val(marker.getLatLng().lng());
});

map.addOverlay(marker);
}
});
</script>
{/literal}