why old text with textOut cleared !!

From:

=?Utf-8?B?aGFkaSBrYXplbWk=?= <hadikazemi@discussions.microsoft.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Sun, 4 Oct 2009 05:20:01 -0700

Message-ID:

<13A9809F-DDE6-4A6A-8D81-7A74DA6E2B44@microsoft.com>

hi
i use these code for add some text in my window:

[code]

        case WM_PAINT:
            hdc = BeginPaint(hWnd, &ps);
            TextOut (hdc, 90, 0,
                        L"Welcome To DirectX Sound Recorder.",
                        lstrlen (L"Welcome To DirectX Sound Recorder.")) ;
            if(whatPrint == 'i'){
                TextOut (hdc, 0, 2 * cyChar,
                            L"Ready For Start...",
                            lstrlen (L"Ready For Start...")) ;
            }else if (whatPrint == 'r'){
                TextOut (hdc, 0, indexOfLineForPrint * cyChar,
                            L"Recording... ",
                            lstrlen (L"Recording... ")) ;
                //indexOfLineForPrint++;
            }else if (whatPrint == 's'){
                TextOut (hdc, 0, indexOfLineForPrint * cyChar,
                            L"Stop! ",
                            lstrlen (L"Stop! ")) ;
                //indexOfLineForPrint++;
            }
            EndPaint(hWnd, &ps);
            break;

[/code]

when i want add some text do like this:

[code]

whatPrint = 'n';
InvalidateRect(g_hWnd,NULL,FALSE);

[/code]

but when i minimize window and maximize it again. i see all text instead
last text cleared. how can i solve this problem ?