function initialize() {
      if (GBrowserIsCompatible()) {          
var map = new GMap2(document.getElementById("map_canvas")); 
map.setMapType(G_SATELLITE_MAP);
map.setCenter(new GLatLng(40.55827,8.313367), 16);             
//icon defionition for bastione 	 
var bastioneIcon = new GIcon(G_DEFAULT_ICON); 	 
bastioneIcon.image = "media/markers/marker3.png"; 	 
bastioneIcon.iconSize = new GSize(20, 34); 	 
bastioneIcon.shadowSize = new GSize(0, 0); 	 
bastioneIcon.iconAnchor = new GPoint(10, 30); 
//icon defionition for civica 	 
var civicaIcon = new GIcon(G_DEFAULT_ICON); 	 
civicaIcon.image = "media/markers/marker4.png"; 	 
civicaIcon.iconSize = new GSize(20, 34); 	 
civicaIcon.shadowSize = new GSize(0, 0); 	 
civicaIcon.iconAnchor = new GPoint(0, 25); 
//markerOptions = { icon:bastioneIcon };  	 
//icon definition for cathedral 	 
var cathedralIcon = new GIcon(G_DEFAULT_ICON); 	 
cathedralIcon.image = "media/markers/marker5.png"; 	 
cathedralIcon.iconSize = new GSize(20, 34); 	 
cathedralIcon.shadowSize = new GSize(0, 0); 	 
cathedralIcon.iconAnchor = new GPoint(10, 30); 
//icon definition for marina 	 
var marinaIcon = new GIcon(G_DEFAULT_ICON); 	 
marinaIcon.image = "media/markers/marker2.png"; 	 
marinaIcon.iconSize = new GSize(20, 34); 	 
marinaIcon.shadowSize = new GSize(0, 0); 	 
marinaIcon.iconAnchor = new GPoint(10, 30); 	   
//icon definition for alberto 	 
var albertoIcon = new GIcon(G_DEFAULT_ICON); 	 
albertoIcon.image = "media/markers/marker6.png"; 	 
albertoIcon.iconSize = new GSize(20, 34); 	 
albertoIcon.shadowSize = new GSize(0, 0); 	 
albertoIcon.iconAnchor = new GPoint(-5, 0); 	   
//icon definition for umberto 	 
var umbertoIcon = new GIcon(G_DEFAULT_ICON); 	 
umbertoIcon.image = "media/markers/marker7.png"; 	 
umbertoIcon.iconSize = new GSize(20, 34); 	 
umbertoIcon.shadowSize = new GSize(0, 0); 	 
umbertoIcon.iconAnchor = new GPoint(-5, 0); 
//icon definition for walls 	 
var wallsIcon = new GIcon(G_DEFAULT_ICON); 	 
wallsIcon.image = "media/markers/marker1.png"; 	 
wallsIcon.iconSize = new GSize(20, 34); 	 
wallsIcon.shadowSize = new GSize(0, 0); 	 
wallsIcon.iconAnchor = new GPoint(10, 30); 	   	  	 	   	  	 
var mapTypeControl = new GMapTypeControl();          
var topRight = new GControlPosition(G_ANCHOR_TOP_RIGHT, new GSize(10,10));          
var bottomRight = new GControlPosition(G_ANCHOR_BOTTOM_RIGHT, new GSize(10,10));  	 	 	 
//var marker = new GMarker(point);  	          
//this function constructs the info box 	  

function createMarker(point,html) {          
var marker = new GMarker(point, markerOptions);          
GEvent.addListener(marker, "click", function() {            
marker.openInfoWindowHtml(html);         });          
return marker;       	}  	 
function createMarker2(point) {          
var marker = new GMarker(point, markerOptions);          
return marker;       	}  
   //map.addOverlay(marker); 	 
//map.addOverlay(marker, markerOptions);  
//create bastione marker 	 
markerOptions = { icon:bastioneIcon }; 	 
var point = new GLatLng(40.560086,8.31443); 	 
var marker = createMarker(point,'<div style="width:240px"><A href="http://www.algherosardinia.net/oldtown.html#bastione">Bastione La Maddalena</a><P><A href="http://www.algherosardinia.net/oldtown.html#bastione"><IMG height=120 alt="Bastione La Maddalena" src="220/alghero-old-town-bastione-la-maddalena-2.jpg" width=220 border=0></a></div>') 
map.addOverlay(marker);  	
//create civica marker 	 
markerOptions = { icon:civicaIcon }; 	 
var point = new GLatLng(40.559598,8.314003); 	 
var marker = createMarker(point,'<div style="width:240px"><A href="http://www.algherosardinia.net/oldtown.html#civica">Piazza Civica</a><P><A href="http://www.algherosardinia.net/oldtown.html#civica"><IMG height=120 alt="Piazza Civica" src="220/alghero-sardinia-piazza-civica.jpg" width=220 border=0></a></div>') 	 
map.addOverlay(marker);   
//create cathedral marker 	 
markerOptions = { icon:cathedralIcon }; 	 
var point = new GLatLng(40.559235,8.312619); 	 
var marker = createMarker(point,'<div style="width:240px"><A href="http://www.algherosardinia.net/oldtown.html#cathedral">Cathedral</a><P><A href="http://www.algherosardinia.net/oldtown.html#cathedral"><IMG height=120 alt="Alghero Cathedral" src="220/alghero-sardinia-cathedral-campanile.jpg" width=220 border=0></a></div>') 	 
map.addOverlay(marker);   
//create marina marker 	 
markerOptions = { icon:marinaIcon }; 	 
var point = new GLatLng(40.560908,8.311204); 	 
var marker = createMarker(point,'<div style="width:240px"><A href="http://www.algherosardinia.net/oldtown.html#marina">Marina</a><P><A href="http://www.algherosardinia.net/oldtown.html#marina"><IMG height=120 alt="Alghero Marina" src="220/alghero-old-town-marina.jpg" width=220 border=0></a></div>')  
map.addOverlay(marker);   
//create alberto marker 
markerOptions = { icon:albertoIcon }; 	 
var point = new GLatLng(40.558355,8.313601); 	 	 
var marker = createMarker(point,'<div style="width:240px"><A href="http://www.algherosardinia.net/oldtown.html#alberto">Via Carlo Alberto</a><P><A href="http://www.algherosardinia.net/oldtown.html#alberto"><IMG height=120 alt="Via Carlo Alberto" src="220/alghero-old-town-carlo-alberto.jpg" width=220 border=0></a></div>')  
map.addOverlay(marker);   
//create umberto marker 	 
markerOptions = { icon:umbertoIcon }; 	 
var point = new GLatLng(40.558206,8.312893); 	 
var marker = createMarker(point,'<div style="width:240px"><A href="http://www.algherosardinia.net/oldtown.html#umberto">Via Principe Umberto</a><P><A href="http://www.algherosardinia.net/oldtown.html#umberto"><IMG height=120 alt="Via Principe Umberto" src="220/alghero-via-principe-umberto-2.jpg" width=220 border=0></a></div>')  
map.addOverlay(marker); 
//create walls marker 	 
markerOptions = { icon:wallsIcon }; 	 
var point = new GLatLng(40.559863,8.310908); 	 
var marker = createMarker(point,'<div style="width:240px"><A href="http://www.algherosardinia.net/oldtown.html#walls">Walls</a><P><A href="http://www.algherosardinia.net/oldtown.html#walls"><IMG height=120 alt="walls" src="220/alghero-oldtown-ramparts.jpg" width=220 border=0></a></div>')  
map.addOverlay(marker);       
//map.addOverlay(new GMarker(point, markerOptions));          	 	 
//add zoom controls 	 
map.addControl(mapTypeControl, topRight); 	  
GEvent.addListener(map, "dblclick", function() {
            map.removeControl(mapTypeControl);            
map.addControl(new GMapTypeControl(), bottomRight);         });          
map.addControl(new GLargeMapControl()); 	 }      }