VBA Code needs to check for Shared Workbook

[Newby]

Does anyone have some VBA Code that will check to see if the workbook is
currently "Shared"? The problem that I have is that I have an auto comments
feature that adds a cell comment whenever a change is made, I discovered that
when I use a text = cmt.text for a shared workbook it actually copies the
cell comments back into the comment box twice, this doubling effect makes for
very large and repeated comments, whereas when you use this comment feature
on a non shared workbook then cmt.text is needed to keep the existing
comments into the comment box.