There is quite a bit to keep track of when opening and saving documents. You need
to know when to use the SaveAsDialog and when not to. You need to know if a
document is being saved for the first time or whether you are just saving
changes to an existing document.

This project show how and when to Open, Save, and Save As documents. 

OpenSaveAsSave.zip

File_and_Menubar

Open, Save, and Save As