function on(imgname)
{
	if (document.images)
        document[imgname].src = eval(imgname + "_on.src");
}

function off(imgname)
{
	if (document.images)
	document[imgname].src = eval(imgname + "_off.src");
}

if (document.images)
{

var nav_buero_off = new Image();
nav_buero_off.src = "/pic/startmenu/buero.off.jpg";
var nav_projekte_off = new Image();
nav_projekte_off.src = "/pic/startmenu/projekte.off.jpg";
var nav_kontakt_off = new Image();
nav_kontakt_off.src = "/pic/startmenu/kontakt.off.jpg";
var nav_news_off = new Image();
nav_news_off.src = "/pic/startmenu/news.off.jpg";


var nav_buero_on = new Image();
nav_buero_on.src = "/pic/startmenu/buero.on.jpg";
var nav_projekte_on = new Image();
nav_projekte_on.src = "/pic/startmenu/projekte.on.jpg";
var nav_kontakt_on = new Image();
nav_kontakt_on.src = "/pic/startmenu/kontakt.on.jpg";
var nav_news_on = new Image();
nav_news_on.src = "/pic/startmenu/news.on.jpg";

}