// Steuerung der Navigationsleiste
var setname = '';
var img_format = '';

function show(myImg, format) {
	document.images[myImg].src = "../images/" + myImg + "_dn." + format;
	setname = myImg;
	img_format = format;
}

function hide() {
	if (document.images[setname]) {
		document.images[setname].src = "../images/" + setname + "_up." + img_format;
		setname = '';
		img_format = '';
	}
}