// Text vergroessern 
increase = new Image;
increase.src = "images/schaltflaechen/font_increase.gif";

decrease = new Image;
decrease.src = "images/schaltflaechen/font_decrease.gif";

function changeFontSize() {
  if (document.images["font"].src == decrease.src) {
        document.images["font"].src = increase.src;
        document.images["font"].setAttribute("alt","Schrift vergrößern");
        document.getElementsByTagName("link")[1].disabled = true;
  } else {
        document.images["font"].src = decrease.src;
        document.images["font"].setAttribute("alt","Schrift verkleinern");
        document.getElementsByTagName("link")[1].disabled = false;
  }
}
window.document.onload = document.getElementsByTagName("link")[1].disabled = true;