// preloading images
if (document.images) {
 img_on =new Image();  
 img_on.src ="additional/images/einstieg2.png";
 
 img_off=new Image();  
 img_off.src="additional/images/einstieg1.png."; 
}


function handleOver() { 
 if (document.images) 
   document.schafsinn_enter.src=img_on.src;
}

function handleOut() {
 if (document.images) 
   document.schafsinn_enter.src=img_off.src;
}