HHWIN_BUTTON_FAVORITES     = (1 shl 17); // not implemented
  {$EXTERNALSYM HHWIN_BUTTON_FAVORITES}
{$ENDIF}
  HHWIN_BUTTON_JUMP1         = (1 shl 18);
  {$EXTERNALSYM HHWIN_BUTTON_JUMP1}
  HHWIN_BUTTON_JUMP2         = (1 shl 19);
  {$EXTERNALSYM HHWIN_BUTTON_JUMP2}
  HHWIN_BUTTON_ZOOM          = (1 shl 20);
  {$EXTERNALSYM HHWIN_BUTTON_ZOOM}
  HHWIN_BUTTON_TOC_NEXT      = (1 shl 21);
  {$EXTERNALSYM HHWIN_BUTTON_TOC_NEXT}
  HHWIN_BUTTON_TOC_PREV      = (1 shl 22);
  {$EXTERNALSYM HHWIN_BUTTON_TOC_PREV}

  HHWIN_DEF_BUTTONS = HHWIN_BUTTON_EXPAND or HHWIN_BUTTON_BACK or
                      HHWIN_BUTTON_OPTIONS or HHWIN_BUTTON_PRINT;
  {$EXTERNALSYM HHWIN_DEF_BUTTONS}

// Button IDs

  IDTB_EXPAND       = 200;
  {$EXTERNALSYM IDTB_EXPAND}
  IDTB_CONTRACT     = 201;
  {$EXTERNALSYM IDTB_CONTRACT}
  IDTB_STOP         = 202;
  {$EXTERNALSYM IDTB_STOP}
  IDTB_REFRESH      = 203;
  {$EXTERNALSYM IDTB_REFRESH}
  IDTB_BACK         = 204;
  {$EXTERNALSYM IDTB_BACK}
  IDTB_HOME         = 205;
  {$EXTERNALSYM IDTB_HOME}
  IDTB_SYNC         = 206;
  {$EXTERNALSYM IDTB_SYNC}
  IDTB_PRINT        = 207;
  {$EXTERNALSYM IDTB_PRINT}
  IDTB_OPTIONS      = 208;
  {$EXTERNALSYM IDTB_OPTIONS}
  IDTB_FORWARD      = 209;
  {$EXTERNALSYM IDTB_FORWARD}
  IDTB_NOTES        = 210;                 // not implemented
  {$EXTERNALSYM IDTB_NOTES}
  IDTB_BROWSE_FWD   = 211;
  {$EXTERNALSYM IDTB_BROWSE_FWD}
  IDTB_BROWSE_BACK  = 212;
  {$EXTERNALSYM IDTB_BROWSE_BACK}
  IDTB_CONTENTS     = 213;                 // not implemented
  {$EXTERNALSYM IDTB_CONTENTS}
  IDTB_INDEX        = 214;                 // not implemented
  {$EXTERNALSYM IDTB_INDEX}
  IDTB_SEARCH       = 215;                 // not implemented
  {$EXTERNALSYM IDTB_SEARCH}
  IDTB_HISTORY      = 216;                 // not implemented
  {$EXTERNALSYM IDTB_HISTORY}
{$IFDEF HTMLHELP11}
  IDTB_BOOKMARKS    = 217;                 // not implemented
  {$EXTERNALSYM IDTB_BOOKMARKS}
{$ENDIF}
{$IFDEF HTMLHELP12}
  IDTB_FAVORITES    = 217;                 // not implemented
  {$EXTERNALSYM IDTB_FAVORITES}
{$ENDIF}
  IDTB_JUMP1        = 218;
  {$EXTERNALSYM IDTB_JUMP1}
  IDTB_JUMP2        = 219;
  {$EXTERNALSYM IDTB_JUMP2}
  IDTB_CUSTOMIZE    = 221;
  {$EXTERNALSYM IDTB_CUSTOMIZE}
  IDTB_ZOOM         = 222;
  {$EXTERNALSYM IDTB_ZOOM}
  IDTB_TOC_NEXT     = 223;
  {$EXTERNALSYM IDTB_TOC_NEXT}
  IDTB_TOC_PREV     = 224;
  {$EXTERNALSYM IDTB_TOC_PREV}

// Notification codes

  HHN_FIRST         = -860;
  {$EXTERNALSYM HHN_FIRST}
  HHN_LAST          = -879;
  {$EXTERNALSYM HHN_LAST}

  HHN_NAVCOMPLETE   = (HHN_FIRST - 0);
  {$EXTERNALSYM HHN_NAVCOMPLETE}
  HHN_TRACK         = (HHN_FIRST - 1);
  {$EXTERNALSYM HHN_TRACK}
  HHN_WINDOW_CREATE = (HHN_FIRST - 2);
  {$EXTERNALSYM HHN_WINDOW_CREATE}

type
  PHHLastError = ^THHLastError;
  tagHH_LAST_ERROR = packed record
    cbStruct: Integer;      // size of this structure
    hr: HRESULT;            // the last error code.
    description: PWideChar; // a description of the error (unicode string - BSTR).
  end;
  THHLastError = tagHH_LAST_ERROR;

  PHHNNotify = ^THHNNotify;
  tagHHN_NOTIFY = packed record
    hdr: NMHDR;
    pszUrl: PCSTR;                         // multibyte null-terminated string
  end;
  {$EXTERNALSYM tagHHN_NOTIFY}
  HHN_NOTIFY = tagHHN_NOTIFY;
  {$EXTERNALSYM HHN_NOTIFY}
  THHNNotify = tagHHN_NOTIFY;

  PHHPopup = ^THHPopup;
  tagHH_POPUP = packed record
    cbStruct: Integer;                     // sizeof this structure
    hinst: HINST;                          // instance handle for string resource
    idString: UINT;                        // string resource id, or text id if pszFile is specified in HtmlHelp call
    pszText: LPCTSTR;                      // used if idString is zero
    pt: TPoint;                            // top center of popup window
    clrForeGround: TColorRef;              // use -1 for default
    clrBackground: TColorRef;               // use -1 for default
    rcMargins: TRect;                      // amount of space between edges of window and text, -1 for each member to ignore
    pszFont: LPCTSTR;                      // facename, point size, char set, BOLD ITALIC UNDERLINE
  end;
  {$EXTERNALSYM tagHH_POPUP}
  HH_POPUP = tagHH_POPUP;
  {$EXTERNALSYM HH_POPUP}
  THHPopup = tagHH_POPUP;

  PHHAKLink = ^THHAKLink;
  tagHH_AKLINK = packed record
    cbStruct: Integer;                     // sizeof this structure
    fReserved: BOOL;                       // must be FALSE (really!)
    pszKeywords: LPCTSTR;                  // semi-colon separated keywords
    pszUrl: LPCTSTR;                       // URL to jump to if no keywords found (may be NULL)
    pszMsgText: LPCTSTR;                   // Message text to display in MessageBox if pszUrl is NULL and no keyword match
    pszMsgTitle: LPCTSTR;                  // Message text to display in MessageBox if pszUrl is NULL and no keyword match
    pszWindow: LPCTSTR;                    // Window to display URL in
    fIndexOnFail: BOOL;                    // Displays index if keyword lookup fails.
  end;
  {$EXTERNALSYM tagHH_AKLINK}
  HH_AKLINK = tagHH_AKLINK;
  {$EXTERNALSYM HH_AKLINK}
  THHAKLink = tagHH_AKLINK;

const
  HHWIN_NAVTYPE_TOC          = 0;
  {$EXTERNALSYM HHWIN_NAVTYPE_TOC}
  HHWIN_NAVTYPE_INDEX        = 1;
  {$EXTERNALSYM HHWIN_NAVTYPE_INDEX}
  HHWIN_NAVTYPE_SEARCH       = 2;
  {$EXTERNALSYM HHWIN_NAVTYPE_SEARCH}
{$IFDEF HTMLHELP11}
  HHWIN_NAVTYPE_BOOKMARKS    = 3;
  {$EXTERNALSYM HHWIN_NAVTYPE_BOOKMARKS}
  HHWIN_NAVTYPE_HISTORY      = 4;          //not implemented
  {$EXTERNALSYM HHWIN_NAVTYPE_HISTORY}
{$ENDIF}
{$IFDEF HTMLHELP12}
  HHWIN_NAVTYPE_FAVORITES    = 3;
  {$EXTERNALSYM HHWIN_NAVTYPE_FAVORITES}
  HHWIN_NAVTYPE_HISTORY      = 4;          //not implemented
  {$EXTERNALSYM HHWIN_NAVTYPE_HISTORY}
  HHWIN_NAVTYPE_AUTHOR       = 5;
  {$EXTERNALSYM HHWIN_NAVTYPE_AUTHOR}
  HHWIN_NAVTYPE_CUSTOM_FIRST = 11;
  {$EXTERNALSYM HHWIN_NAVTYPE_CUSTOM_FIRST}
{$ENDIF}

  IT_INCLUSIVE = 0;
  {$EXTERNALSYM IT_INCLUSIVE}
  IT_EXCLUSIVE = 1;
  {$EXTERNALSYM IT_EXCLUSIVE}
  IT_HIDDEN    = 2;
  {$EXTERNALSYM IT_HIDDEN}

type
  PHHEnumIT = ^THHEnumIT;
  tagHH_ENUM_IT = packed record
    cbStruct: Integer;        // size of this structure
    iType: Integer;           // the type of the information type ie. Inclusive, Exclusive, or Hidden
    pszCatName: LPCSTR;       // Set to the name of the Category to enumerate the info types in a category; else NULL
    pszITName: LPCSTR;        // volitile pointer to the name of the infotype. Allocated by call. Caller responsible for freeing
    pszITDescription: LPCSTR; // volitile pointer to the description of the infotype.
  end;
  {$EXTERNALSYM tagHH_ENUM_IT}
  HH_ENUM_IT = tagHH_ENUM_IT;
  {$EXTERNALSYM HH_ENUM_IT}
  PHH_ENUM_IT = ^tagHH_ENUM_IT;
  {$EXTERNALSYM PHH_ENUM_IT}
  THHEnumIT = tagHH_ENUM_IT;

  PHHEnumCat = ^THHEnumCat;
  tagHH_ENUM_CAT = packed record
    cbStruct: Integer;         // size of this structure
    pszCatName: LPCSTR;        // volitile pointer to the category name
    pszCatDescription: LPCSTR; // volitile pointer to the category description
  end;
  {$EXTERNALSYM tagHH_ENUM_CAT}
  HH_ENUM_CAT = tagHH_ENUM_CAT;
  {$EXTERNALSYM HH_ENUM_CAT}
  PHH_ENUM_CAT = ^tagHH_ENUM_CAT;
  {$EXTERNALSYM PHH_ENUM_CAT}
  THHEnumCat = tagHH_ENUM_CAT;

  PHHSetInfoType = ^THHSetInfoType;
  tagHH_SET_INFOTYPE = packed record
    cbStruct: Integer;        // the size of this structure
    pszCatName: LPCSTR;       // the name of the category, if any, the InfoType is a member of.
    pszInfoTypeName: LPCSTR;  // the name of the info type to add to the filter
  end;
  {$EXTERNALSYM tagHH_SET_INFOTYPE}
  HH_SET_INFOTYPE = tagHH_SET_INFOTYPE;
  {$EXTERNALSYM HH_SET_INFOTYPE}
  PHH_SET_INFOTYPE = ^tagHH_SET_INFOTYPE;
  {$EXTERNALSYM PHH_SET_INFOTYPE}
  THHSetInfoType = tagHH_SET_INFOTYPE;

  HH_INFOTYPE = DWORD;
  {$EXTERNALSYM HH_INFOTYPE}
  PHH_INFOTYPE = ^HH_INFOTYPE;
  {$EXTERNALSYM PHH_INFOTYPE}
  PHHInfoType = ^THHInfoType;
  THHInfoType = HH_INFOTYPE;

const
  HHWIN_NAVTAB_TOP    = 0;
  {$EXTERNALSYM HHWIN_NAVTAB_TOP}
  HHWIN_NAVTAB_LEFT   = 1;
  {$EXTERNALSYM HHWIN_NAVTAB_LEFT}
  HHWIN_NAVTAB_BOTTOM = 2;
  {$EXTERNALSYM HHWIN_NAVTAB_BOTTOM}

  HH_MAX_TABS         = 19;
  {$EXTERNALSYM HH_MAX_TABS}

  HH_TAB_CONTENTS     = 0;
  {$EXTERNALSYM HH_TAB_CONTENTS}
  HH_TAB_INDEX        = 1;
  {$EXTERNALSYM HH_TAB_INDEX}
  HH_TAB_SEARCH       = 2;
  {$EXTERNALSYM HH_TAB_SEARCH}
{$IFDEF HTMLHELP11}
  HH_TAB_BOOKMARKS    = 3;
  {$EXTERNALSYM HH_TAB_BOOKMARKS}
  HH_TAB_HISTORY      = 4;
  {$EXTERNALSYM HH_TAB_HISTORY}
{$ENDIF}
{$IFDEF HTMLHELP12}
  HH_TAB_FAVORITES    = 3;
  {$EXTERNALSYM HH_TAB_FAVORITES}
  HH_TAB_HISTORY      = 4;
  {$EXTERNALSYM HH_TAB_HISTORY}
  HH_TAB_AUTHOR       = 5;
  {$EXTERNALSYM HH_TAB_AUTHOR}

  HH_TAB_CUSTOM_FIRST = 11;
  {$EXTERNALSYM HH_TAB_CUSTOM_FIRST}
  HH_TAB_CUSTOM_LAST  = HH_MAX_TABS;
  {$EXTERNALSYM HH_TAB_CUSTOM_LAST}

  HH_MAX_TABS_CUSTOM  = HH_TAB_CUSTOM_LAST - HH_TAB_CUSTOM_FIRST + 1;
  {$EXTERNALSYM HH_MAX_TABS_CUSTOM}
{$ENDIF}

// HH_DISPLAY_SEARCH Command Related Structures and Constants

  HH_FTS_DEFAULT_PROXIMITY = -1;
  {$EXTERNALSYM HH_FTS_DEFAULT_PROXIMITY}

type
  PHHFtsQuery = ^THHFtsQuery;
  tagHH_FTS_QUERY = packed record
    cbStruct: Integer;         // Sizeof structure in bytes.
    fUniCodeStrings: BOOL;     // TRUE if all strings are unicode.
    pszSearchQuery: LPCTSTR;   // String containing the search query.
    iProximity: LongInt;       // Word proximity.
    fStemmedSearch: BOOL;      // TRUE for StemmedSearch only.
    fTitleOnly: BOOL;          // TRUE for Title search only.
    fExecute: BOOL;            // TRUE to initiate the search.
    pszWindow: LPCTSTR;        // Window to display in
  end;
  {$EXTERNALSYM tagHH_FTS_QUERY}
  HH_FTS_QUERY = tagHH_FTS_QUERY;
  {$EXTERNALSYM HH_FTS_QUERY}
  THHFtsQuery = tagHH_FTS_QUERY;

  PHHWinType = ^THHWinType;
  tagHH_WINTYPE = packed record
    cbStruct: Integer;      // IN: size of this structure including all Information Types
    fUniCodeStrings: BOOL;  // IN/OUT: TRUE if all strings are in UNICODE