Code:

// 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;