hwndToolTips = CreateWindow(TOOLTIPS_CLASS,
                            NULL,
                            WS_POPUP | TTS_NOPREFIX | TTS_BALLOON,
                             0 ,  0 ,
                             0 ,  0 ,
                            NULL, NULL,
                            g_hinst,
                            NULL);
if (hwndToolTips)
{
// Do the standard ToolTip coding. 
    TOOLINFO ti;

    ti.cbSize = sizeof(ti);
    ti.uFlags = TTF_TRANSPARENT | TTF_CENTERTIP;
    ti.hwnd = hwnd;
    ti.uId =  0 ;
    ti.hinst = NULL;
    ti.lpszText = LPSTR_TEXTCALLBACK;

    GetClientRect(hwnd, &ti.rect);
    SendMessage(hwndToolTips, TTM_ADDTOOL,  0 , (LPARAM) &ti );
}