// map (Central Image Variant)

var mapCentralImageOn = new Array();
var mapCentralImageOff = null;


// Preload map images
function mapCentralInit() {
	if (document.images) {
		
		// for each map, preload both states and put filename in an associative array
		for (var i = 0; i < mapCentralImageOnFiles.length; i++) {
			mapCentralImageOn[i] = new Image();
			mapCentralImageOn[i].src = mapCentralImageDirectory + mapCentralImageOnFiles[i];
		}
		
		mapCentralImageOff = new Image();
		mapCentralImageOff.src = mapCentralImageDirectory + mapCentralImageOffFile;
	}
}


// On state activation
function mapCentralOn(num) {
	if (document.images && mapCentralImageOn[num]) {
		
		// maps in layers in NS4 require a different image reference
		if (mapCentralImageLayerName != '' && document.layers) {
			document.layers[mapCentralImageLayerName].document.images[mapCentralImageTagName].src = mapCentralImageOn[num].src;
		}
		
		// non-layer maps in NS4 and all maps in other browsers
		else if (document.images[mapCentralImageTagName]) {
			document.images[mapCentralImageTagName].src = mapCentralImageOn[num].src;
		}
	}
}


// Off state activation
function mapCentralOff() {
	if (document.images && mapCentralImageOff) {

		// maps in layers in NS4 require a different image reference
		if (mapCentralImageLayerName != '' && document.layers) {
			document.layers[mapCentralImageLayerName].document.images[mapCentralImageTagName].src = mapCentralImageOff.src;
		}
		
		// non-layer maps in NS4 and all maps in other browsers
		else if (document.images[mapCentralImageTagName]) {
			document.images[mapCentralImageTagName].src = mapCentralImageOff.src;
		}
	}
}


// map with state function (not used in standard maps; included for flexability)
function mapCentralSetCurrent(num) {
	mapCentralImageOff.src = mapCentralImageOn[num].src;
}