Invokes the help facility (obsolete)
Supported Platforms: Windows only
(acad_helpdlg helpfile topic)
Type: String
The path and file name of the help file to open.
Type: String
The name of the topic to display in the help file.
Type: String or nil
Returns the file name of the help file if it is found; otherwise, nil is returned if the file is not found.
This externally defined function has been replaced by the built-in help function. It is provided for compatibility with earlier releases of AutoCAD.