I am glad that you introduced me to UserForms and I must say
that your instructions were very understandable and easy to follow.
I succeeded in setting it all up, so that I can call the window showing
all my sheets.
I think this is the method I prefer to implement.
Thanks again.

You are quite welcome. If you think you will want to use this idea on other
projects, you may want to do what I did... install the code on a clean
workbook (or just take the one you have and delete all data and any VB code
(other than the code I gave you of course) and then save the workbook as an
Excel Template. That way, whenever you start a new workbook, just pick that
template instead of a blank workbook and the functionality will be
immediately available. If this is a new concept to you, write back with your
Excel version number and I'll try to provide instructions to you for that
version.

Rick Rothstein (MVP - Excel)