function status: string; 
begin 
  if getkeystate(VK_INSERT) = 0 
    then result := 'Einfügen' 
  else result := 'Überschreiben'; 
end; 
 
procedure TForm1.FormCreate(Sender: TObject); 
begin 
  keypreview := true; 
  label1.caption := status; 
end; 
 
procedure TForm1.FormKeyUp(Sender: TObject; var Key: Word; 
  Shift: TShiftState); 
begin 
  if key = VK_INSERT then label1.caption := status; 
end;