var MapSources = new Array ();

   MapSources[1] = new Image();
   MapSources[1].src = "images/map_img/mappa_1.jpg";
   MapSources[2] = new Image();
   MapSources[2].src = "images/map_img/mappa_2.jpg";
   MapSources[3] = new Image();
   MapSources[3].src = "images/map_img/mappa_3.jpg";
 
var MapDefault = new Image();
 MapDefault.src="images/map_img/mappa.jpg";
		
function RollMapOn(ImgNum)
   {
   document.RollerMap.src=MapSources[ImgNum].src;
   }

function RollMapOff()
   {
   document.RollerMap.src=MapDefault.src;
   }