CHM Files

Microsoft makes an online help system called HTML Help. HTML Help uses the underlying components of Microsoft Internet Explorer to display help content. HTML Help supports HTML, ActiveX, Java, scripting (JavaScript and Microsoft Visual Basic Script), and HTML image formats (.jpeg, .gif, .png).

To create online help for your application, use the authoring tool in HTML Help called HTML Help Workshop (HHW). HHW will help you create a compiled HTML file that ends with the .chm extension. The Official Microsoft Help Authoring Kit from Microsoft Press has more information about help authoring. Contact Microsoft for more information about compiled HTML files.

$WINHELP will automatically detect the .chm file extension and invoke the Microsoft HTML Help Viewer application (hh.exe) to access the file. Only two operation codes are supported, HELP-CONTENTS and HELP-CONTEXT. When the operation code is HELP-CONTENTS, $WINHELP simply passes the specified compiled HTML help file name as a command-line argument to hh.exe. When the second parameter to $WINHELP, the operation code, is HELP-CONTEXT, $WINHELP constructs a command line using the following template:

hh.exe -mapid context_id help_file

where help_file is the first parameter to $WINHELP and context_id is the third parameter to $WINHELP. For example, the COBOL call:

CALL "$WINHELP" USING "c:\mydir\myhelp.chm", HELP-CONTENTS

translates to the system command line:

hh c:\mydir\myhelp.chm


CALL "$WINHELP" USING "c:\mydir\myhelp.chm", 

translates to:

hh -mapid 72 c:\mydir\myhelp.chm