' zunächst die benötigten API-Deklarationen
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 
 
Private Const SWP_NOSIZE = &H1 
Private Const SWP_NOZORDER = &H4 
Private Const SWP_NOMOVE = &H2 
Private Const SWP_DRAWFRAME = &H20 
Private Const GWL_STYLE = (-16) 
Private Const WS_THICKFRAME = &H40000 
 
' Ermöglicht die Größe eines Objekts zur Laufzeit zu ändern 
' 
' bStatus = True, Größenänderung einschalten 
' bStatus = False, Größenänderung abschalten 
' =====================================================
Public Sub DoResize(hWndParent As Long, _ 
  hWndObject As Long, ByVal bStatus As Boolean) 
 
  Dim Result As Long 
 
  Result = GetWindowLong(hWndObject, GWL_STYLE) Or _ 
    WS_THICKFRAME 
  If Not bStatus Then _ 
    Result = Result - WS_THICKFRAME 
 
  SetWindowLong hWndObject, GWL_STYLE, Result
  SetWindowPos hWndObject, hWndParent, 0, 0, 0, 0, _ 
    SWP_NOZORDER Or SWP_NOSIZE Or SWP_NOMOVE Or _ 
    SWP_DRAWFRAME 
End Sub