// array of description names
var descriptions = new Array("frankfurt","koeln","duesseldorf");

function showDescription(name) {
	for (index in descriptions) {
		hideLayer("desc" + descriptions[index]);
		if (name == descriptions[index]) {
			hideLayer("link" + descriptions[index]);
		} else {
			showLayer("link" + descriptions[index]);
		}
	}
	showLayer("desc"+name);
}