var preloadedImages = new Array();
var counterOpened;
var interOpened;
function preloadImages(locationFolder) {
	if(document.images) {
			var i, args = preloadImages.arguments; 
			
			for(i=1; i<args.length; i++) {
				preloadedImages[args[i]]   = new Image(); 
				preloadedImages[args[i]].src   = locationFolder + args[i];
			}
	}
}
function rollOn(imageName, imageExt) {
	if(document.images)
		document.images[imageName].src = preloadedImages[imageName + "_over."+imageExt].src;
}
function rollOff(imageName, imageExt) {
	if(document.images)
		document.images[imageName].src = preloadedImages[imageName + "_normal."+imageExt].src;
}