Отображение формы в трее

uses ShellAPI;

type
   TForm1 = class(TForm)
     Button1: TButton;
     procedure WMICON(var msg: TMessage); message WM_USER;
     procedure Button1Click(Sender: TObject);
   private
     { Private declarations }
   public
     { Public declarations }
   end;
    TDUMMYUNIONNAME = record
    case Integer of
       0: (uTimeout: UINT);
       1: (uVersion: UINT);
    end;
    TNewNotifyIconData = record
       cbSize: DWORD;
       Wnd: HWND;
       uID: UINT;
       uFlags: UINT;
       uCallbackMessage: UINT;
       hIcon: HICON;
       szTip: array[0..127] of Char;
       dwState: DWORD;
       dwStateMask: DWORD;
       szInfo: array[0..255] of Char;
       DUMMYUNIONNAME: TDUMMYUNIONNAME;
       szInfoTitle: array[0..63] of Char;
       dwInfoFlags: DWORD;
    end;
***
procedure TForm1.Button1Click(Sender: TObject);
var nidata: TNewNotifyIconData;
begin
    With nidata do
    begin
       cbSize:=SizeOf(nidata);
       Wnd:=Handle;
       uID:=0;
       uFlags:=NIF_ICON or NIF_MESSAGE or NIF_TIP;
       uCallBackMessage:=WM_USER;
       hIcon:=Icon.Handle;
       StrPCopy(szTip, 'Yes');
    end;
    Shell_NotifyIcon(NIM_ADD, @nidata);
end;

procedure TForm1.WMICON(var msg: TMessage);
begin
    MessageBox(0, 'SMS-ка пришла', 'Окно', 0);
end;