Access - Error en módulo "modWheelMouse"

Option Compare Database

Option Explicit

Declare PtrSafe 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

    Declare PtrSafe Function SetWindowLong Lib "user32" Alias _

    "SetWindowLongA" (ByVal hwnd As Long, _

    ByVal nIndex As Long, ByVal dwNewLong As Long) As Long

Public Declare PtrSafe Function RegisterWindowMessage& Lib "user32" Alias "RegisterWindowMessageA" _

(ByVal lpString As String)

Public Const GWL_WNDPROC = -4

Public IsHooked As Boolean

Public lpPrevWndProc As Long

Public gHW As Long

Public Sub Hook()

    If IsHooked Then

        'MsgBox "Don't hook it twice without " & _

        ' "unhooking, or you will be unable to unhook it."

        IsHooked = True

    Else

        lpPrevWndProc = SetWindowLong(gHW, GWL_WNDPROC, _

        AddressOf WindowProc)

        IsHooked = True

    End If

End Sub

Public Sub Unhook()

    Dim temp As Long

    temp = SetWindowLong(gHW, GWL_WNDPROC, lpPrevWndProc)

    IsHooked = False

End Sub

Function WindowProc(ByVal hw As Long, ByVal uMsg As _

Long, ByVal wParam As Long, ByVal lParam As Long) As Long

    If uMsg = GetMouseWheelMsg Then

        ' Debug.Print "Message: "; hw, uMsg, wParam, lParam

        WindowProc = 0

    Else

        WindowProc = CallWindowProc(lpPrevWndProc, hw, _

            uMsg, wParam, lParam)

    End If

End Function

Public Function GetMouseWheelMsg() As Long

GetMouseWheelMsg = 522 'this works for Win98/2000, otherwise use

    'RegisterWindowMessage("MSWHEEL_ROLLMSG")

End Function

Declare PtrSafe Function SetWindowLongPtr Lib "user32" Alias _

    "SetWindowLongA" (ByVal hwnd As Long, _

    ByVal nIndex As Long, ByVal dwNewLong As Long) As Long