function downloadGeotagJSON ( serverFile, lat, lon, callback ) {
	var url = 'ajax/' + serverFile + '.php?lat=' + lat + '&lng=' + lon;
	_ajax ( url, function ( reply ) {
		if ( reply )
			var tree = eval( "(" + reply + ")" );
		else
			var tree = {status:true};
		callback(tree);
	} );
}
function nearbyPlace ( lat, lon, callback ) {
	downloadGeotagJSON ( "locationName", lat, lon, callback );
}

function nearbyWeather ( lat, lon, callback ) {
	downloadGeotagJSON ( "weather", lat, lon, callback );
}

function terrainElevation ( lat, lon, callback ) {
	downloadGeotagJSON ( "elevation", lat, lon, callback );
}