IMG_FORMAT  = ".gif";

function wechsel(Bild,Status) {
//	syntaxbeispiel: "onMouseOver="wechsel('abc','on');"
  temp = new Image();
  temp.src = window.document[Bild].src.substring(0,window.document[Bild].src.lastIndexOf("_")) + "_" + Status + IMG_FORMAT;
  window.document[Bild].src = temp.src;

}

function popup(ziel,titel,breite,hoehe,werte) {
  if (werte == 'nothing') werte = "location=no,menubar=no,resizable=no,scrollbars=no,status=no,toolbar=no";
  if (screen.availWidth <= breite || screen.availHeight <= hoehe) {
    links = 1;
    oben = 1;
  }
  else {
    links = 50;
    oben = 50;
  }

  fenster=window.open(''+ziel+'',''+titel+'',''+werte+',width='+breite+',height='+hoehe+',left='+links+',top='+oben+'');
  fenster.focus();
}