C# Constants:

public const IntPtr HWND_BROADCAST = new IntPtr(0xffff);
public const IntPtr HWND_TOP       = new IntPtr(0);
public const IntPtr HWND_BOTTOM    = new IntPtr(1);
public const IntPtr HWND_TOPMOST   = new IntPtr(-1);
public const IntPtr HWND_NOTOPMOST = new IntPtr(-2);
public const IntPtr HWND_MESSAGE   = new IntPtr(-3);

VB.net Constants:

Public Const HWND_BROADCAST As Int32 = &HFFFF
Public Const HWND_TOP As Int32       = &H0
Public Const HWND_BOTTOM As Int32    = &H1
Public Const HWND_TOPMOST As Int32   = -&H1
Public Const HWND_NOTOPMOST As Int32 = -&H2
Public Const HWND_MESSAGE As Int32   = -&H3

Notes:

Used in SendMessage API