//Windows +XP
//Form witch one button and one editbox

type 
  tagEDITBALLOONTIP = record
    cbStruct: Longword;
    pszTitle: PWChar;
    pszText: PWChar;
    ttiIcon: Integer;
  end;
type 
  PEDITBALLOONTIP = ^tagEDITBALLOONTIP;

const
  ECM_FIRST         = $00001500;
  EM_SHOWBALLOONTIP = ECM_FIRST + 3;

procedure TForm1.Button1Click(Sender: TObject);
var
  ebt: tagEDITBALLOONTIP;
  title, Text: Widestring;
  icon: Integer;
begin
  title := 'tooltip!!';
  Text  := 'in editbox :)';
  icon  := 1; //0,1,2,3
  with ebt do
  begin
    cbStruct := SizeOf(ebt);
    pszTitle := PWideChar(title);
    pszText  := PWideChar(Text);
    ttiIcon  := icon;
  end;
  SendMessage(Edit1.Handle, EM_SHOWBALLOONTIP, 0, Longint(@ebt));
end;