[https://docs.microsoft.com/en-us/previous-versions/windows/desktop/htmlhelp/adding-buttons-to-a-help-window](https://docs.microsoft.com/en-us/previous-versions/windows/desktop/htmlhelp/adding-buttons-to-a-help-window)
https://docs.microsoft.com/en-us/previous-versions/windows/desktop/htmlhelp/adding-buttons-to-a-help-window