HOWTO: Use HTML Help API in a Visual Basic Application

      Const HH_DISPLAY_TOPIC = &H0
      Const HH_SET_WIN_TYPE = &H4
      Const HH_GET_WIN_TYPE = &H5
      Const HH_GET_WIN_HANDLE = &H6
      Const HH_DISPLAY_TEXT_POPUP = &HE   ' Display string resource ID or
                                          ' text in a pop-up window.
      Const HH_HELP_CONTEXT = &HF         ' Display mapped numeric value in
                                          ' dwData.
      Const HH_TP_HELP_CONTEXTMENU = &H10 ' Text pop-up help, similar to
                                          ' WinHelp's HELP_CONTEXTMENU.
      Const HH_TP_HELP_WM_HELP = &H11     ' text pop-up help, similar to
                                          ' WinHelp's HELP_WM_HELP.
						

      Declare Function HtmlHelp Lib "hhctrl.ocx" Alias "HtmlHelpA" _
         (ByVal hwndCaller As Long, ByVal pszFile As String, _
         ByVal uCommand As Long, ByVal dwData As Long) As Long
						

      ' HTML Help file launched in response to a button click:
      Private Sub HH_DISPLAY_Click()
      'hWnd is a Long defined elsewhere to be the window handle
      'that will be the parent to the help window.
         Dim hwndHelp As Long
         'The return value is the window handle of the created help window.
         hwndHelp = HtmlHelp(hWnd, "myfile.chm", HH_DISPLAY_TOPIC, 0)
      End Sub

      ' A specific topic identified by the variable ContextID is launched
      ' in response to this button click:
      Private Sub HH_HELP_Click()
         Dim hwndHelp As Long
         'The return value is the window handle of the created help window.
        hwndHelp = HtmlHelp(hWnd, "myfile.chm", HH_HELP_CONTEXT, ContextID)
      End Sub