function PopUp(ziel,f) {
  var w, h, b, bars="", fenster="", d=0, x=0, y=0;
  switch(f)
  {
    case 0: w=0; h=0; b=0; break;
    case 1: w=0; h=0; b=1; break;
    case 2: w=790; h=564; b=0; break;
    case 3: w=790; h=564; b=1; break;
    case 4: w=320; h=430; b=-1; break;
    default: w=0; h=0; b=0; break;
  }
  if (b != -1) bars=",resizable=yes,scrollbars=yes";
  if (b == 1) { bars=",menubar=yes,location=yes,toolbar=no,status=no"+bars; h=h-66; d=22; }
  else d = -44;
  if (w > 0 && h > 0) {
    if (w < screen.availWidth || h < screen.availHeight) {
      x = (screen.availWidth - w - 12) / 2;
      y = (screen.availHeight - h - d) / 2;
      if (window.opera) y = 0; // Opera positioniert unter den Symbolleisten
      if (x < 0 || y < 0) { x=0 ; y=0; }
      else fenster = "width="+w+",height="+h+",";
    }
  }
  fenster += "left="+x+",top="+y+bars;
  var NewPopUp = window.open(ziel,"Heyken",fenster);
  if (NewPopUp) NewPopUp.focus();
  return !NewPopUp;
}