var centerLatitude = 39.670852; 
var centerLongitude = -8.808653; 
var startZoom = 13; 
var map; 
function init() 
{ 
if (GBrowserIsCompatible()) { 
map = new GMap2(document.getElementById("map")); 
map.addControl(new GSmallMapControl());
map.addControl(new GMapTypeControl());
var location = new GLatLng(centerLatitude, centerLongitude); 
map.setCenter(location, startZoom); 
var marker = new GMarker(location) 
map.addOverlay(marker);
} 
} 
window.onload = init;
window.onunload = GUnload;