/// <summary>
        /// Launch the MS Help Viewer to view the last built Microsoft Help Viewer file.  This
        /// will optionally install it first.
        /// </summary>
        /// <param name="sender">The sender of the event</param>
        /// <param name="e">The event arguments</param>
        private void ViewMshcHelpExecuteHandler(object sender, EventArgs e)
        {
            SandcastleProject project = CurrentSandcastleProject;

            var options = this.GeneralOptions;

            if(project != null && options != null)
                using(LaunchMSHelpViewerDlg dlg = new LaunchMSHelpViewerDlg(project, options.MSHelpViewerPath))
                {
                    dlg.ShowDialog();
                }
        }
        /// <summary>
        /// View the last built help output
        /// </summary>
        /// <param name="projectNode">The project node for which to open the help file</param>
        internal void ViewBuiltHelpFile(SandcastleBuilderProjectNode projectNode)
        {
            if(projectNode != null)
            {
                SandcastleProject project = projectNode.SandcastleProject;

                if(project == null)
                    return;

                if((project.HelpFileFormat & HelpFileFormats.HtmlHelp1) != 0)
                    ViewBuiltHelpFile(project, PkgCmdIDList.ViewHtmlHelp);
                else
                    if((project.HelpFileFormat & HelpFileFormats.OpenXml) != 0)
                        ViewBuiltHelpFile(project, PkgCmdIDList.ViewDocxHelp);
                    else
                        if((project.HelpFileFormat & HelpFileFormats.Markdown) != 0)
                            ViewBuiltHelpFile(project, 0);
                        else
                            if((project.HelpFileFormat & HelpFileFormats.Website) != 0)
                                Utility.OpenUrl(projectNode.StartWebServerInstance());
                            else
                            {
                                // This format opens a modal dialog box so we'll use it last if nothing else
                                // is selected.
                                var options = this.GeneralOptions;

                                if(options != null)
                                    using(LaunchMSHelpViewerDlg dlg = new LaunchMSHelpViewerDlg(project,
                                        options.MSHelpViewerPath))
                                    {
                                        dlg.ShowDialog();
                                    }
                            }
            }
        }