Zoom in and zoom out the map with the response wheel in MapX

'Module
Option Explicit
Public Const GWL_WNDPROC = (-4)
Public Const WM_COMMAND = & H111
Public Const WM_MBUTTONDOWN = & H207
Public Const WM_MBUTTONUP = & H208
Public Const WM_MOUSEWHEEL = & H20A
Public Oldwinproc As Long
Public Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hWnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Public 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 Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" (ByVal hWnd As Long, ByVal nIndex As Long) As Long
Public Function FlexScroll (ByVal hWnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
Select Case wMsg
Case WM_MOUSEWHEEL
Select Case wParam
Case-7864320 'roll down
SetCurrentScale "ZoomOut", 2
Case 7864320 'roll up
SetCurrentScale "ZoomIn", 2
End Select