Does the Editor have any shortcut keys?
Yes, they are:

Every time I launch Helpmatic Pro HTML, it tries to access the internet. Why?
Helpmatic Pro HTML is checking if there has been any new versions released lately. If a new version has been released, it will display a HTML page showing you all the new features/bug fixes in the latest version of Helpmatic Pro HTML. You can turn this function off from: Tools Menu > Options > General Tab > Untick "Check for updates".

Where can I get more information on all the various CSS elements and properties?
Microsoft have excellent documentation in their online MSDN librarry.

Where can I get more documentation on HTML Help?
Microsoft provide a free set of help files that go into detail about HTML Help and its various features.

<a href="mk:@MSITStore:helpfile.chm::/topic.htm">click me</a>

Where helpfile.chm is the name of your external help file, and topic.htm is the topic filename.

To display the whole help file including the contents, then paste the following into the HTML editor :

<OBJECT id=hhctrl type="application/x-oleobject"
classid="clsid:adb880a6-d8ff-11cf-9377-00aa003b7a11"
codebase="hhctrl.ocx">
<PARAM name="Command" value="ShortCut">
<PARAM name="Item1" value=",hh.exe,helpfile.chm">
</OBJECT>

<a href="JavaScript:hhctrl.Click()">click me </a>

Where helpfile.chm is the name of your external help file.

So that HTML Help can locate your external help file, you will need to add a registry entry for your help file at :

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\HTML Help

Where does my CHM file get created after compile?
The CHM file will be in your project folder. Look in the title bar of the Helpmatic Pro HTML main window that will display the folder location, or select Explore Project Folder from the Tools menu.

How can I specify a background picture for my topics in a stylesheet?
You can use the following properties of the Body element:

background-image: url(yourpichere.gif)
background-attachment: fixed

When selecting an image for the background-image property, the url() text will automatically get inserted around it. Also, Helpmatic Pro HTML will ask if you want this file added to the additional files list, select Yes.

background-attachment: fixed will keep the image fixed on the page even when you scroll.

How can I use HTML Help in my VB.net application?
Microsoft have a very good MSDN article on their website which explains how to do this :

HOW TO: Provide Context-Sensitive Help or Online Help in a Windows Application by Using Visual Basic .NET

The Help.ShowHelp Method on the System.Windows.Forms.Help object can also be used to open a HTML Help file from within a .net application.

The following code can be used to open a topic where the user uses What's this help for a control.

HelpProvider1.HelpNamespace = "b:\example.chm"
HelpProvider1.SetHelpKeyword(controlName, contextNumber)
HelpProvider1.SetHelpNavigator(controlName, HelpNavigator.TableOfContents)
HelpProvider1.SetHelpNavigator(controlName, HelpNavigator.TopicId)

Where contextNumber is the context number of the topic you wish to show, and controlName is the name of the control you want to assign the What's this help.

How can I link to a help file from Excel using VBA?
You can use this VBA code to launch your help file:

Shell "hh.exe yourhelpfilehere.chm", vbNormalFocus

Or, to specify a specific topic, you can use:

mk:@MSITStore:yourhelpfilehere.chm::/topicfilename.htm

Or, here is some sample code (supplied by Garry Sansom) that allows you to open a help file from VBA.

How can I use HTML Help in my Visual Basic application?
Visual Basic 6 does not directly allow you to link to the chm files. It is quite simple though (and more powerful) to use the API.

Add the following to a module :

' HTML Help declarations
Public Const HH_DISPLAY_TOC = &H1
Public Const HH_DISPLAY_TOPIC = &H0
Public Const HH_DISPLAY_TEXT_POPUP = &HE ' Display string resource ID or text in a pop-up window.
Public Const HH_HELP_CONTEXT = &HF ' Display mapped numeric value in dwData.
Public Const HH_TP_HELP_CONTEXTMENU = &H10 ' Text pop-up help, similar to WinHelp's HELP_CONTEXTMENU.
Public Const HH_TP_HELP_WM_HELP = &H11 ' text pop-up help, similar to WinHelp's HELP_WM_HELP.

Public Declare Function HtmlHelp Lib "hhctrl.ocx" Alias "HtmlHelpA" _
(ByVal lhwndCaller As Long, ByVal sFileName As String, _
ByVal lCommand As Long, ByVal lData As Long) As Long

Then use this function to display topics with the specified context number

Public Sub GetHelp(ByVal lContextNum As Long)
     Dim sHelpFile As String

     ' get filename
     sHelpFile = App.Path & "\YourHelp.chm"

     If lContextNum < 1 Then ' show contents
          HtmlHelp frmYourForm.hwnd, sHelpFile, HH_DISPLAY_TOC, 0
     Else
          HtmlHelp frmYourForm.hwnd, sHelpFile, HH_HELP_CONTEXT, lContextNum
     End If
End Sub

frmYourForm, change this to the name of your main Form.
YourHelp.chm, change this to the name of your help file (it needs to be in the app.path of your application).

You can pass in 0 to display the Contents, or an integer > 0 to display the corresponding topic for the context number.

For a more detailed example, please refer to this MSDN article.

Run("hh","mk:@MSITStore:<SrcDir>\YourHelp.chm::/TopicFileName.htm")

If you want to jump to a specific topic and bookmark or anchor:

Run("hh","mk:@MSITStore:<SrcDir>\YourHelp.chm::/TopicFileName.htm#AnchorName")

YourHelp.chm, change this to the name of your help file.
TopicFileName.htm, the name of the topic you want to display.

Is possible to execute a shell command from a button in my .chm file?
Yes, insert the following into the HTML view of your topic at the location where you wish to insert the button:

<OBJECT id=hhctrl type="application/x-oleobject"
        classid="clsid:adb880a6-d8ff-11cf-9377-00aa003b7a11"
        codebase="hhctrl.ocx#Version=4,74,8793,0"
        width=100
        height=100> 

    <PARAM name="Command" value="ShortCut">
    <PARAM name="Button" value="Text:Click Me">
    <PARAM name="Item1" value=",C:\myfile.txt,"> </OBJECT>

Change c:\myfile.txt to the filename of the file you wish to launch, and change Click Me to the text you wish to show in the button.