//<![CDATA[
function customGetTileURL(a,b) {
      //converts tile x,y into keyhole string
      if (b>12) { return "Subcounty_12_2006_DDWGS84_region-tiles/blank-tile.png"; };

      var c=Math.pow(2,b);
      var x=360/c*a.x-180;
      var y=180-360/c*a.y;
      var x2=x+360/c;
      var y2=y-360/c;
      var lon=x; //Math.toRadians(x); //would be lon=x+lon0, but lon0=0 degrees
      var lat=(2.0*Math.atan(Math.exp(y/180*Math.PI))-Math.PI/2.0)*180/Math.PI; //in degrees
      var lon2=x2;
      var lat2=(2.0*Math.atan(Math.exp(y2/180*Math.PI))-Math.PI/2.0)*180/Math.PI; //in degrees
      var tileBounds=new GLatLngBounds(new GLatLng(lat2,lon),new GLatLng(lat,lon2));

      if (!tileBounds.intersects(mapBounds)) { return "Subcounty_12_2006_DDWGS84_region-tiles/blank-tile.png"; };
        var d=a.x;
        var e=a.y;
        var f="t";
        for(var g=0;g<b;g++){
            c=c/2;
            if(e<c){
                if(d<c){f+="q"}
                else{f+="r";d-=c}
            }
            else{
                if(d<c){f+="t";e-=c}
                else{f+="s";d-=c;e-=c}
            }
        }
        return "Subcounty_12_2006_DDWGS84_region-tiles/"+f+".png"
    }
    

    function changeOpacity(op) {
	//this works as long as there are at least two map types
        var current=map.getCurrentMapType();
        if (current==map.getMapTypes()[0])
        	map.setMapType(map.getMapTypes()[1]);
	else
		map.setMapType(map.getMapTypes()[0]);
        opacity=op;
        map.setMapType(current); //was map.getMapTypes()[1]
    }


    function getWindowHeight() {
        if (window.self&&self.innerHeight) {
            return self.innerHeight;
        }
        if (document.documentElement&&document.documentElement.clientHeight) {
            return document.documentElement.clientHeight;
        }
        return 0;
    }

    function resizeMapDiv() {
        //Resize the height of the div containing the map.
        //Do not call any map methods here as the resize is called before the map is created.
    	var d=document.getElementById("map");
        var offsetTop=0;
        for (var elem=d; elem!=null; elem=elem.offsetParent) {
            offsetTop+=elem.offsetTop;
        }
        var height=getWindowHeight()-offsetTop-16;
        if (height>=0) {
            d.style.height=height+"px";
        }
    }


    function load() {
      if (GBrowserIsCompatible()) {
        //resizeMapDiv();
        var copyright = new GCopyright(1,
                              new GLatLngBounds(new GLatLng(-90, -180),
                                                new GLatLng(90, 180)),
                              0,
                              "UBOS/UNICEF");
        var copyrightCollection = new GCopyrightCollection("Subcounties:");
        copyrightCollection.addCopyright(copyright);

        //create a custom G_NORMAL_MAP layer
        var n_tileLayers = [ G_NORMAL_MAP.getTileLayers()[0], new GTileLayer(copyrightCollection , 0, 17)];
        n_tileLayers[1].getTileUrl = customGetTileURL;
        n_tileLayers[1].isPng = function() { return false; };
        n_tileLayers[1].getOpacity = function() { return opacity; };
        var n_customMap = new GMapType(n_tileLayers, new GMercatorProjection(13), n_buttonText,
            {maxResolution:12, minResolution:0, errorMessage:"Data not available"});

        //create a custom G_SATELLITE_MAP layer
        var s_tileLayers = [ G_SATELLITE_MAP.getTileLayers()[0], new GTileLayer(copyrightCollection , 0, 17)];
        s_tileLayers[1].getTileUrl = customGetTileURL;
        s_tileLayers[1].isPng = function() { return false; };
        s_tileLayers[1].getOpacity = function() { return opacity; };
        var s_customMap = new GMapType(s_tileLayers, new GMercatorProjection(13), s_buttonText,
            {maxResolution:12, minResolution:0, errorMessage:"Data not available"});

        //Now create the custom map. Would normally be G_NORMAL_MAP,G_SATELLITE_MAP,G_HYBRID_MAP
        //map = new GMap2(document.getElementById("map"),{mapTypes:[n_customMap,s_customMap]});
        map = new GMap2(document.getElementById("map"));
        map.addMapType(s_customMap);
        map.addControl(new GLargeMapControl());
        map.addControl(new GMapTypeControl());
        map.enableContinuousZoom();
        map.enableScrollWheelZoom();
        map.setCenter(new GLatLng(centreLat, centreLon), default_zoom_level, s_customMap);
      }
    }
//---->
//]]>