Detecting that the window is closing by subclassing , Doesn't work :(

[msayed2004]

I have this code in a Module (warning not a safe subclass routine be careful) :

Option Explicit
 
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 CallWindowProc Lib "user32" Alias "CallWindowProcA" (ByVal lpPrevWndFunc As Long, ByVal hWnd As Long, ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
 
Public Const GWL_WNDPROC = (-4)
Dim PrevProc As Long
Private Const WM_CLOSE = &H10
 
Public Sub HookForm(FormName As Form)
PrevProc = SetWindowLong(FormName.hWnd, GWL_WNDPROC, AddressOf WindowProc)
End Sub
 
Public Sub UnHookForm(FormName As Form)
SetWindowLong FormName.hWnd, GWL_WNDPROC, PrevProc
End Sub
 
Public Function WindowProc(ByVal hWnd As Long, ByVal uMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
If uMsg = WM_CLOSE Then Beep ' <- I want my actions here but to simplify it I remove my code & added Beep.
WindowProc = CallWindowProc(PrevProc, hWnd, uMsg, wParam, lParam)
End Function

& this for the Form :

Option Explicit
 
Private Sub Form_Load()
HookForm Me
End Sub
 
Private Sub Form_Unload(Cancel As Integer)
UnHookForm Me
End Sub

Detecting the WM_CLOSE message doesn't work for me , I tried WM_DESTROY = &H2 and WM_NCDESTROY = &H82 but nothing work , for testing I tried WM_SYSCOMMAND = &H112 and it work with any system command , my question is what I missed in that routine & how I can make it work????