login_a = new Image();
	login_a.src = "./assets/images/design/login_nonactive.png";
	login_b = new Image();
	login_b.src = "./assets/images/design/login_active.png";

	register_a = new Image();
	register_a.src = "./assets/images/design/register_nonactive.png";
	register_b = new Image();
	register_b.src = "./assets/images/design/register_active.png";
	
	function tauschen(Bildname,Tauschbildname)
		{
		document.getElementById(Bildname).src = eval(Tauschbildname + ".src")
		}