Private Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" ( _
  ByVal hwnd As Long, ByVal nIndex As Long) As Long
Private Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" ( _
ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Private Declare Function SetWindowPos Lib "user32" (ByVal hwnd As Long, ByVal _
hWndInsertAfter As Long, ByVal x As Long, ByVal y As Long, ByVal cx As Long, _
ByVal cy As Long, ByVal wFlags As Long) As Long
 
Const GWL_STYLE = (-16)
Const WS_OVERLAPPED = &H0&
Const WS_CAPTION = &HC00000
Const SWP_FRAMECHANGED = &H20
Const SWP_NOMOVE = &H2
Const SWP_NOSIZE = &H1
 
Private Sub Command1_Click()
  SetTitle Me, False ' ausblenden
End Sub
 
Private Sub Command2_Click()
  SetTitle Me, True ' einblenden
End Sub
 
Private Sub SetTitle(frmForm As Form, visible As Boolean)
 
Dim lngStyle As Long, lngFormDC As Long
 
lngStyle = GetWindowLong(frmForm.hwnd, GWL_STYLE)
 
If visible Then
    lngStyle = lngStyle Or (WS_OVERLAPPED Or WS_CAPTION)
Else
    lngStyle = lngStyle And Not (WS_OVERLAPPED Or WS_CAPTION)
End If
 
SetWindowLong frmForm.hwnd, GWL_STYLE, lngStyle
SetWindowPos frmForm.hwnd, 0, 0, 0, 0, 0, SWP_FRAMECHANGED Or SWP_NOMOVE Or _
  SWP_NOSIZE
 
End Sub