function open(URI1) {
  Frame1=eval("parent.mainFrame");
  Frame1.location.href = URI1;
}

function changenavi(URI1,URI2){
  Frame1=eval("parent.mainFrame");
  Frame2=eval("parent.naviFrame");
  Frame1.location.href = URI1;
  Frame2.location.href = URI2;
}

function changeimg(imgsrc){
  myElement = document.getElementById("navimap");
  myElement.src=imgsrc;
}

function opentermine(){
  /*var i= new Date();
  var monatszahl= i.getMonth();
  var monat = new Array("jan","feb","mar","apr","mai","jun","jul","aug","sep","okt","nov","dez");
  changenavi("termine_"+monat[monatszahl]+".htm","navi.htm");*/
  changenavi("termine.htm","navi.htm");
}