function Tasten (Maus) {
  if (!Maus)
    Maus = window.event;
  if (Maus.button) {
    if (Maus.button == 2) {
      alert('Webgestaltung:\n\n        A.S. Webdesign 2009\n \nCopyright by: Alexander Scholl'); }
    if (Maus.button == 3) {
      alert('Webgestaltung:\n\n        A.S. Webdesign 2009\n \nCopyright by: Alexander Scholl'); }}}
document.onmousedown = Tasten;
document.onmouseup = Tasten;