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);
IntPtr HWND_MESSAGE   = new IntPtr(-3);

VB Constants:

HWND_BROADCAST As IntPtr = new IntPtr(65535);
HWND_TOP As IntPtr       = new IntPtr(0);
HWND_BOTTOM As IntPtr    = new IntPtr(1);
HWND_TOPMOST As IntPtr   = new IntPtr(-1);
HWND_NOTOPMOST As IntPtr = new IntPtr(-2);
HWND_MESSAGE As IntPtr   = new IntPtr(-3);

Notes:

Used in SendMessage api