Code: Alles auswählen
procedure TForm1.Button1Click(Sender: TObject);
var
ch: Char;
begin
if Edit1.Text = '' then
exit;
ch := Edit1.Text[1];
case ch of
'ä': ShowMessage('klein');
'Ä': ShowMessage('groß');
else ShowMessage('etwas anderes...');
end;
end;