d6 dhtmledit 做querystatus后，再关闭窗口失败

Question

达人帮忙看下
下面是源码，两个窗体
一：窗体1：
unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs,Unit2, StdCtrls;type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  Form1: TForm1;
  f: TForm2;implementation{$R *.dfm}procedure TForm1.Button1Click(Sender: TObject);
begin
  f :=  tform2.Create(nil);
  f.ShowModal;
end;procedure TForm1.Button2Click(Sender: TObject);
begin
  f.DHTMLEdit1.Destroy;  
  button2.caption := '1';
end;end.二：窗体2
unit Unit2;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, OleCtrls, DHTMLEDLib_TLB;type
  TForm2 = class(TForm)
    DHTMLEdit1: TDHTMLEdit;
    procedure DHTMLEdit1EndDrag(Sender, Target: TObject; X, Y: Integer);
    procedure DHTMLEdit1DisplayChanged(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  Form2: TForm2;implementation{$R *.dfm}procedure TForm2.DHTMLEdit1DisplayChanged(Sender: TObject);
begin
  dhtmledit1.QueryStatus(DECMD_BOLD);
end;end.