//Klassenname fuer zoombare Bilder
		class_zoom = 'zoom';
		
		//Klassenname fuer grosse Ansicht
		class_big = 'gross';
	
		listen('load', window, function() {
			mlisten('click', getElementsByClass(class_zoom, 'div'), event_zoom);
	  	});
	  	
	  	function event_zoom(e) {
	  		if (hasClass(this, class_big))
	  			this.className = this.className.substr(0,this.className.length - (class_big.length + 1));
	  		else
	  			this.className += ' ' + class_big;
	  	}