I have a DrExplain help facility (css, js, htm files) that I want to use in a SharePoint 2013 custom web part via a popup window. This works well in .NET applications but not in SharePoint. The DrExplain folder is in a SharePoint SiteAssets folder.
What I have tried:
Google a lot. Put the DrExplain in ControlTemplates but have not found how to reference it.