function createYahooMarker(lat, lon, num, title) {
        var geopoint = new YGeoPoint(lat,lon);
	var myImage = new YImage(); 
	var marker = new YMarker(geopoint,myImage); 
	marker.addLabel(num);
	marker.addAutoExpand(title);
	map.addOverlay(marker);
	return marker; 
}