function zamen(nazev_obr, novy_obr) {
		document.images[nazev_obr].src=novy_obr;
	}

function popup(url) {
	window.open(url,'popup','width=460, height=450, location=no , menubar=no , toolbar=no , status=no , directories=no , scrollbars=no , resizable=no');
}