No, that is not correct. First, you should have stated that you're using VBA to begin with so that someone trying to answer your question would know what environment you're working in. As I said in my last post, VBA has a built-in shortcut named Application. So the code would be:
Application.Shutdown()
However, since you're calling your form from ArcMap's OpenDocument event you will not be able to close ArcMap or load another document because ArcMap is already in the process of opening a document. You can only do these kind of things after the document has been loaded.