var pic1, pic2;
pic1 = new Image();
pic1.src = "/bilder/lamuca.gif";
pic2 = new Image();
pic2.src = "/bilder/lamucus.gif"; 
 
function rotator() {
    if (document.images["lamuca"].src == pic1.src) {
       document.images["lamuca"].src = pic2.src;
       }
	else {
       document.images["lamuca"].src = pic1.src;
       }
    }

window.setInterval("rotator()", 8000);