 Scroll bar messages:
Private Const WM_VSCROLL = &amp;H115
Private Const WM_HSCROLL = &amp;H114
Private Const WM_MOUSEWHEEL = &amp;H20A

' Mouse wheel stuff:
Private Const WHEEL_DELTA = 120
Private Const WHEEL_PAGESCROLL = -1
Private Const SPI_GETWHEELSCROLLLINES = &amp;H68

' Old school Wheel Mouse is not supported in this class.
' NT3.51 or Win95 only
'// Class name for MSWHEEL.EXE's invisible window
'// use FindWindow to get hwnd to MSWHEEL
Private Const MSH_MOUSEWHEEL = "MSWHEEL_ROLLMSG"
Private Const M