bottoni_01 = new Image();
bottoni_01.src = "images2/zurueck.jpg";
bottoni_01_over = new Image();
bottoni_01_over.src = "images2/zurueck-over.jpg";
bottoni_01_down = new Image();
bottoni_01_down.src = "images2/zurueck-down.jpg";


function changeImage(imgName, imgObj, divID, visible)
{
   if (document.images) 
   {
       if(document.images[imgName])
         document.images[imgName].src = eval(imgObj+".src");
   }
   if (document.getElementById(divID))
   {
   		if (visible)
   			document.getElementById(divID).style.visibility = "visible";
   		else
   			document.getElementById(divID).style.visibility = "hidden";
   }
}