C# Constants:

IntPtr HWND_BROADCAST = new IntPtr(0xffff);
IntPtr HWND_TOP    = new IntPtr(0);
IntPtr HWND_BOTTOM     = new IntPtr(1);
IntPtr HWND_TOPMOST    = new IntPtr(-1);
IntPtr HWND_NOTOPMOST  = new IntPtr(-2);

VB Constants:

TODO

Notes:

Used in SendMessage api