function Maus_auf_raute(Element){

  
  Element.style.borderLeft="3px solid gray"; 
  Element.style.borderTop="3px solid silver"; 
  Element.style.borderBottom="3px solid white"; 
  Element.style.borderRight="3px solid white";

}

function Maus_aus_raute(Element){
  Element.style.borderWidth='0px';

}