C/Visual C - Visual C++ No RECONOCE ghThisInstance

Pues asi es amigos si alguien sabe por que, soy novato en esto de visual c++, asi que agradecira cualquier opinion.

Marca estos mensajes de error:

error C2065: 'ghThisInstance' : undeclared identifier
error C2440: '=' : cannot convert from 'int' to 'struct HINSTANCE__ *'


Intento correr este ejemplo que vi en MSDN pero no funciona.

void CreateMyTooltip (HWND hwnd)
{
// struct specifying control classes to register
INITCOMMONCONTROLSEX iccex;
HWND hwndTT; // handle to the ToolTip control
// struct specifying info about tool in ToolTip control
TOOLINFO ti;
unsigned int uid = 0; // for ti initialization
char strTT[30] = "This is your ToolTip string.";
LPTSTR lptstr = strTT;
RECT rect; // for client area coordinates

/* INITIALIZE COMMON CONTROLS */
iccex.dwICC = ICC_WIN95_CLASSES;
iccex.dwSize = sizeof(INITCOMMONCONTROLSEX);
InitCommonControlsEx(&iccex);

/* CREATE A TOOLTIP WINDOW */
hwndTT = CreateWindowEx(WS_EX_TOPMOST,
TOOLTIPS_CLASS,
NULL,
WS_POPUP | TTS_NOPREFIX | TTS_ALWAYSTIP,
CW_USEDEFAULT,
CW_USEDEFAULT,
CW_USEDEFAULT,
CW_USEDEFAULT,
hwnd,
NULL,
ghThisInstance,
NULL
);

SetWindowPos(hwndTT,
HWND_TOPMOST,
0,
0,
0,
0,
SWP_NOMOVE | SWP_NOSIZE | SWP_NOACTIVATE);

/* GET COORDINATES OF THE MAIN CLIENT AREA */
GetClientRect (hwnd, &rect);

/* INITIALIZE MEMBERS OF THE TOOLINFO STRUCTURE */
ti.cbSize = sizeof(TOOLINFO);
ti.uFlags = TTF_SUBCLASS;
ti.hwnd = hwnd;
ti.hinst = ghThisInstance;
ti.uId = uid;
ti.lpszText = lptstr;
// ToolTip control will cover the whole window
ti.rect.left = rect.left;
ti.rect.top = rect.top;
ti.rect.right = rect.right;
ti.rect.bottom = rect.bottom;

/* SEND AN ADDTOOL MESSAGE TO THE TOOLTIP CONTROL WINDOW */
SendMessage(hwndTT, TTM_ADDTOOL, 0, (LPARAM) (LPTOOLINFO) &ti);
}