'In module'
Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
 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 )
Private Const WM_CONTEXTMENU As Long = &H7B

Public MessageThread As Long

Public Function WindowProcCB(ByVal hwnd As Long, ByVal uMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
 If uMsg = WM_CONTEXTMENU Then uMsg =  0 
 WindowProcCB = CallWindowProc(MessageThread, hwnd, uMsg, wParam, lParam)
End Function


'Form_Load'
  MessageThread = SetWindowLong(Text1.hwnd, GWL_WNDPROC, AddressOf WindowProcCB)

'Form_Unload'
'  SetWindowLong Text1.hwnd, GWL_WNDPROC, MessageThread