ExcelBanter - Password can be changed in 2000

Hi,
I am sure this has been covered already but I can't seem to find it.

I have put together a workbook in Excel 2000 that will be sent out to
co-workers, users and viewers. I want the users to be able to make
changes to the cells but not the viewers, they just need to be able to
see the final product. I have protected each worksheet using a password
(Tools|Protection|Protect Sheet| put in a password.)

My question is this. When a user, who knows the password, goes to
re-lock the sheet after making changes types in the password
incorrectly/changes the password it is changes for that sheet. For
example if they original password was 1234 and they re-protect the
sheet and type in 2345 Excel 2000 picks up the new password. The other
users won't know of this change and the person who made the change
might not realized they did it.

Is there any way to make sure this doesn't happen? Can I set the
password so it can't be changed?

Thanks!