function addGEBCOMapType() {
	var copyright = new GCopyright(1, new GLatLngBounds(new GLatLng(-90,-180), new GLatLng(90,180)), 0, "NVS");
		
	var copyrightCollection = new GCopyrightCollection('Map Data:');
	copyrightCollection.addCopyright(copyright);

	GEBCOMapTileUrl = function(t, z) {
		//return tileServerURL()+"gebcosat/"+z+"/"+t.y+"/"+t.x+".png"
		return tileServerURL()+"tiles/gebcosat/"+z+"/"+t.y+"/"+t.x+".png"
	}
	
	var tilelayers = [new GTileLayer(copyrightCollection, 0, 17)];
  tilelayers[0].getTileUrl = GEBCOMapTileUrl;

	GEBCO_MAP = new GMapType(tilelayers, new GMercatorProjection(18), "GEBCO", {shortName:"GEBCO"});
	map.addMapType(GEBCO_MAP);
}

function addReliefMapType() { //from maps-for-free
	var copyright = new GCopyright(1, new GLatLngBounds(new GLatLng(-90,-180), new GLatLng(90,180)), 0, "NVS");
		
	var copyrightCollection = new GCopyrightCollection('Map For Free:');
	copyrightCollection.addCopyright(copyright);

	ReliefMapTileUrl = function(t, z) {
		return "http://maps-for-free.com/layer/relief/z"+z+"/row"+t.y+"/"+z+"_"+t.x+"-"+t.y+".jpg";
	}
	
	var tilelayers = [new GTileLayer(copyrightCollection, 0, 17)];
  tilelayers[0].getTileUrl = ReliefMapTileUrl;

	RELIEF_MAP = new GMapType(tilelayers, new GMercatorProjection(18), "Relief", {shortName:"Relief"});
	map.addMapType(RELIEF_MAP);
}