if(!$modell)
{
  out qq{<form action="baseportal.pl?htx=$htx"><input type="hidden" name="htx" value="$htx"><select name="modell">};
  get "Modell==*";
  while(get_next)
  {
    out "<option>$Modell" unless $modelle{$Modell}++;
  }
  out "</select></form>";

{
  out qq{<form action="baseportal.pl?htx=$htx"><input type="hidden" name="htx" value="$htx"><input type="hidden" name="modell" value="$modell"><select name="typ">};
  get "Typ==* Modell==$modell";
  while(get_next)
  {
    out "<option>$Typ" unless $typen{$Typ}++;
  }
  out "</select></form>";
} else
{
  get "Typ==$typ Modell==$modell";
  while(get_next)
  {
    out "Ersatzteil: $Ersatzteil - Preis: $Preis<br>";
  }
}