var hotels_icon = new Image();
hotels_icon.src = "icons/hotels.gif";
var hotels_over = new Image();
hotels_over.src = "icons/hotels_over.gif";

var restaurants_icon = new Image();
restaurants_icon.src = "icons/restaurants.gif";
var restaurants_over = new Image();
restaurants_over.src = "icons/restaurants_over.gif";

var shopping_icon = new Image();
shopping_icon.src = "icons/shopping.gif";
var shopping_over = new Image();
shopping_over.src = "icons/shopping_over.gif";

var nightlife_icon = new Image();
nightlife_icon.src = "icons/nightlife.gif";
var nightlife_over = new Image();
nightlife_over.src = "icons/nightlife_over.gif";

var airport_icon = new Image();
airport_icon.src = "icons/airport.gif";
var airport_over = new Image();
airport_over.src = "icons/airport_over.gif";

var attractions_icon = new Image();
attractions_icon.src = "icons/attractions.gif";
var attractions_over = new Image();
attractions_over.src = "icons/attractions_over.gif";

var panoramas_icon = new Image();
panoramas_icon.src = "icons/panoramas.gif";
var panoramas_over = new Image();
panoramas_over.src = "icons/panoramas_over.gif";

var mrt_stations_icon = new Image();
mrt_stations_icon.src = "icons/mrt_stations.gif";
var mrt_stations_over = new Image();
mrt_stations_over.src = "icons/mrt_stations_over.gif";

var visitor_centres_icon = new Image();
visitor_centres_icon.src = "icons/visitor_centres.gif";
var visitor_centres_over = new Image();
visitor_centres_over.src = "icons/visitor_centres_over.gif";