Protect sheet function is not working

[ebe]

Hi
I have a workbook in which i can't edit any cells in any worksheet because Protect sheet function is greyed out on the ribbon and can't unprotect the sheets. I tried everthing but for this particular workbbok i cant get Protect Sheet function working.. I was using the same for last months data and it works just fine..but after updating it for this month, somehow protect sheet function is not working. I cant even copy sheets to a new workbook so i could post an example here..Could you let me know how to get the Protect Sheet activated?

Thanks

[martindwilson]

make sure you havent accidently shared the work book

[ebe]

yeah on the top by the name of the workbook it says [Shared]..how can i undo that?

[ebe]

Thanks for the help..i found out how..all you have to do is go to Review->Shareworkbook and uncheck Aloow changes box