GetAliases(ComboBox1.Items)
procedure GetAliases(const AList: TStrings);
var
 i: Integer;
 Desc: DBDesc;
 Buff: array[0..254] of char;
begin
 // list all BDE aliases
 Session.GetAliasNames(AList);
 for i := AList.Count - 1 downto 0 do
 begin
  StrPCopy(Buff, AList[i]);
  Check(DbiGetDatabaseDesc(Buff, @Desc));
  // no Paradox, please
  if StrPas(Desc.szDBType) = 'STANDARD' then
  AList.Delete(i)
 end
end;