function uml(letter,formnum,elementnum) {
  formelem=document.forms[formnum].elements[elementnum];
  if (letter=="ae") formelem.value += "ä";
  if (letter=="ue") formelem.value += "ü";
  if (letter=="oe") formelem.value += "ö";
  if (letter=="Ae") formelem.value += "Ä";
  if (letter=="Ue") formelem.value += "Ü";
  if (letter=="Oe") formelem.value += "Ö";
  if (letter=="sz") formelem.value += "ß";
  formelem.focus();
}