初学求助:DELPHI7 的弹出菜单,如何实现"复制"，"粘贴"操作

procedure TForm1.mecutClick(Sender: TObject);
begin
if (richedit1.SelLength <> 0) then
begin
clipboard.AsText:=richedit1.SelText ;
richedit1.ClearSelection ;
end;
end;

procedure TForm1.mecopyClick(Sender: TObject);
begin

if (richedit1.SelLength <> 0) then
clipboard.AsText:=richedit1.SelText ;
end;

procedure TForm1.mepasteClick(Sender: TObject);
begin
if(clipboard.AsText <> '') then
richedit1.SelText :=clipboard.AsText;

end;
procedure TForm1.meundoClick(Sender: TObject);
begin
Richedit1.Undo;
end;

在uses 中加入clipbrd.