Grabbed from this url (may only contain most useful definitions): http://www.groupsrv.com/dotnet/about52848.html WM_NULL = 0x0000, WM_CREATE = 0x0001, WM_DESTROY = 0x0002, WM_MOVE = 0x0003, WM_SIZE = 0x0005, WM_ACTIVATE = 0x0006, WM_SETFOCUS = 0x0007,