function preload() {
	world = new Image(303,154);
	world.src = "images/home_map/world.gif";

	north_america = new Image(303,154);
	north_america.src = "images/home_map/north_america.gif";
	
	latin_america = new Image(303,154);
	latin_america.src = "images/home_map/latin_america.gif";
	
	europe = new Image(303,154);
	europe.src = "images/home_map/europe.gif";
	
	africa = new Image(303,154);
	africa.src = "images/home_map/africa.gif";
	
	asia = new Image(303,154);
	asia.src = "images/home_map/asia.gif";
}
function switchImage(continent) {
	switch(continent) {
		case 'world':
			document.world_map.src = world.src;
			break;
		case 'north_america':
			document.world_map.src = north_america.src;
			break;
		case 'latin_america':
			document.world_map.src = latin_america.src;
			break;
		case 'europe':
			document.world_map.src = europe.src;
			break;
		case 'africa':
			document.world_map.src = africa.src;
			break;
		case 'asia':
			document.world_map.src = asia.src;
			break;
		}
	return true;
}
preload();