function newImage(arg) {
	if( document.images ) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if( document.images && (preloadFlag == true) ) {
		for(var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

var preloadFlag = false;
function preloadImages() {
	if( document.images ) {
		map_18_over = newImage("images/map_over_01.gif");
		map_17_over = newImage("images/map_over_02.gif");
		map_16_over = newImage("images/map_over_03.gif");
		map_15_over = newImage("images/map_over_04.gif");
		map_14_over = newImage("images/map_over_05.gif");
		map_13_over = newImage("images/map_over_06.gif");
		map_12_over = newImage("images/map_over_07.gif");
		map_11_over = newImage("images/map_over_08.gif");
		map_10_over = newImage("images/map_over_09.gif");
		map_09_over = newImage("images/map_over_10.gif");
		map_08_over = newImage("images/map_over_11.gif");
		map_07_over = newImage("images/map_over_12.gif");
		map_06_over = newImage("images/map_over_13.gif");
		map_05_over = newImage("images/map_over_14.gif");
		map_04_over = newImage("images/map_over_15.gif");
		map_03_over = newImage("images/map_over_16.gif");
		map_02_over = newImage("images/map_over_17.gif");
		map_01_over = newImage("images/map_over_18.gif");
		preloadFlag = true;
	}
}