function showDiv(select) 
{ 
var wert = select.options[select.options.selectedIndex].value; 
var obj1 = document.getElementById('preis'); 
var obj2 = document.getElementById('mietepacht'); 
if(!obj1) return; 
if(!obj2) return; 
obj1.style.display = (wert == "0") ? "block" : "none"; 
obj2.style.display = (wert == "1,2") ? "block" : "none"; 
}