function  loadRedNatura()
{
var tilelayer = new GTileLayer(GCopyrightCollection(''), 8, 12);
tilelayer.getTileUrl = function(tile,zoom) {
                var ymax = 1 << zoom;
                var y = ymax - tile.y -1;
                return "costasData/layerdata/"+zoom+"/"+tile.x+"/"+y+".png";                  
                                            }
                                             
            tilelayer.isPng = function() { return true;};
            tilelayer.getOpacity = function() { return 0.40; }
			
			var myTileLayer = new GTileLayerOverlay(tilelayer);			
			map.addOverlay(myTileLayer);




}	

function loadLeyenda()
{

var screenOverlay = new GScreenOverlay("costasData/leyendacostas.png",
                                                  new GScreenPoint(437, 22),
                                                  new GScreenPoint(0, 0),
                                                  new GScreenSize(200, 110));
map.addOverlay(screenOverlay); 

}