I have an Excel 2010 spreadsheet that will be accessed by many users. I want it to be read-only, unless they put in a password, then they can edit. This must be able to be done, because I work with a spreadsheet that was created by someone else that when you open it, a little box pops up asking for the password, which you can enter, or you can press read only.

I don't want to do the "mark as final" option, because then they can't edit if they want. I also already know how to password protect my spreadsheet, but that doesn't give you the option to read only. I don't want people editing if they don't have the password.