var centreLat=0.0;
    var centreLon=0.0;
    var initialZoom=0;
    var imageWraps=false; 
    var map; //the GMap2 itself;


/////////////////////
//Custom projection
/////////////////////
    function CustomProjection(a,b){
	this.imageDimension=65536;
	this.pixelsPerLonDegree=[];
	this.pixelOrigin=[];
	this.tileBounds=[];
	this.tileSize=256;
        this.isWrapped=b;
	var b=this.tileSize;
	var c=1;
	for(var d=0;d<a;d++){
          var e=b/2;
          this.pixelsPerLonDegree.push(b/360);
          this.pixelOrigin.push(new GPoint(e,e));
          this.tileBounds.push(c);
          b*=2;
          c*=2
        }
    }
 
    CustomProjection.prototype=new GProjection();
  
    CustomProjection.prototype.fromLatLngToPixel=function(latlng,zoom){
        var c=Math.round(this.pixelOrigin[zoom].x+latlng.lng()*this.pixelsPerLonDegree[zoom]);
        var d=Math.round(this.pixelOrigin[zoom].y+(-2*latlng.lat())*this.pixelsPerLonDegree[zoom]);
        return new GPoint(c,d)
    };

    CustomProjection.prototype.fromPixelToLatLng=function(pixel,zoom,unbounded){
        var d=(pixel.x-this.pixelOrigin[zoom].x)/this.pixelsPerLonDegree[zoom];
        var e=-0.5*(pixel.y-this.pixelOrigin[zoom].y)/this.pixelsPerLonDegree[zoom];
        return new GLatLng(e,d,unbounded)
    };

    CustomProjection.prototype.tileCheckRange=function(tile,zoom,tilesize){
        var tileBounds=this.tileBounds[zoom];
	if (tile.y<0 || tile.y >= tileBounds) {return false;}
        if (this.isWrapped) {
		if (tile.x<0 || tile.x>=tileBounds) { 
			tile.x = tile.x%tileBounds; 
			if (tile.x < 0) {tile.x+=tileBounds} 
		}
	}
	else { 
        	if (tile.x<0 || tile.x>=tileBounds) {return false;}
	}  
  	return true;
    }
      
    CustomProjection.prototype.getWrapWidth=function(zoom) {
        return this.tileBounds[zoom]*this.tileSize;
    }
////////////////////////////////////////////////////////////////////////////

    function customGetTileURL(a,b) {
      //converts tile x,y into keyhole string

      var c=Math.pow(2,b);
        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 "gmapImage_hq-tiles2/"+f+".jpg"
    }
function addMarker(latitude, longitude, description) {
    var marker = new GMarker(new GLatLng(latitude, longitude));

    GEvent.addListener(marker, 'click',
        function() {
            marker.openInfoWindowHtml(description);
        }
    );

    map.addOverlay(marker);
}



function init()
{
    if (GBrowserIsCompatible()) {
              var copyright = new GCopyright(1,
                              new GLatLngBounds(new GLatLng(-90, -180),
                                                new GLatLng(90, 180)), 0,"");
        var copyrightCollection = new GCopyrightCollection("");
        copyrightCollection.addCopyright(copyright);

        //create a custom picture layer
        var pic_tileLayers = [ new GTileLayer(copyrightCollection , 0, 17)];
        pic_tileLayers[0].getTileUrl = customGetTileURL;
        pic_tileLayers[0].isPng = function() { return false; };
        pic_tileLayers[0].getOpacity = function() { return 1.0; };
        var proj=new CustomProjection(9,imageWraps);
        var pic_customMap = new GMapType(pic_tileLayers, proj, "Pic",
            {maxResolution:5, minResolution:0, errorMessage:"End"});


        //Now create the custom map. 
		//Would normally be G_NORMAL_MAP,G_SATELLITE_MAP,G_HYBRID_MAP
        map = new GMap2(document.getElementById("map"),{mapTypes:[pic_customMap]});
        map.addControl(new GMapTypeControl());
    	map.enableDoubleClickZoom();
		map.enableContinuousZoom();
		map.enableScrollWheelZoom();
		var mt = map.getMapTypes();

		var slidePosition = new GControlPosition(G_ANCHOR_TOP_RIGHT, new GSize(45, 60));
		map.addControl(new GLargeMapControl(), slidePosition);
        map.setCenter(new GLatLng(0,-125), 0);
		//allow the user to click the map to create a marker
    }
}





window.onload = init;
window.onunload = GUnload;