function turnOn (imageName) {
	
	if (document.images) {
		imgSource = eval(imageName + "_on.src");
		//alert(document[imageName]);
		if (document[imageName]) { 
			document[imageName].src = imgSource;
			//alert(document[imageName].name);
		} else if (activeMenuID) {
			imgTarget = eval('document.'+activeMenuID+'.document.images[imageName]');
			imgTarget.src = imgSource;
		}
	}
}
    
function turnOff (imageName) {
	if (document.images) {
		imgSource = eval(imageName + "_off.src");
		if (document[imageName]) {
			document[imageName].src = imgSource;
		} else if (activeMenuID) {
			imgTarget = eval('document.'+activeMenuID+'.document.images[imageName]');
			imgTarget.src = imgSource;
		}
	}
}