// This example doesn't use TReplaceDialog
// Ohne Benutzung von TReplaceDialog
function Search_And_Replace(RichEdit: TRichEdit;
 SearchText, ReplaceText: string): Boolean;
var
 startpos, Position, endpos: integer;
begin
 startpos := 0;
 with RichEdit do
 begin
  endpos := Length(RichEdit.Text);
  Lines.BeginUpdate;
  while FindText(SearchText, startpos, endpos, [stMatchCase])<>-1 do
  begin
  endpos := Length(RichEdit.Text) - startpos;
  Position := FindText(SearchText, startpos, endpos, [stMatchCase]);
  Inc(startpos, Length(SearchText));
  SetFocus;
  SelStart := Position;
  SelLength := Length(SearchText);
  richedit.clearselection;
  SelText := ReplaceText;
  end;
  Lines.EndUpdate;
 end;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
 Search_And_Replace(Richedit1, 'OldText', 'NewText');
end;