function zeigeGrossbild(bild) {
  document.getElementById("grossbild").src = bild;
}

function zeigeTermin(termin) {
  window.open("termine/" + termin, "termin", "width=800,height=600,left=" + ((screen.width - 800) / 2) + ",top=" + ((screen.height - 600) / 2) + ",scrollbars=yes");
}