how to delete a tab if the file is shared?

Hi all,

I have a document and 3 tabs at the bottom (Sheet1, Sheet2 & Sheet3)
I wish to delete Sheet3, for this I right click 'Sheet3' and for some reason, the option 'delete' is not highlighted.

* the file is Shared (not sure this has something to do with that).

Thanks for any pointers

thats why ,there are lots of things you cant do with shared workbooks.
unshare workbook then delete ,simple as that

how do you do that (unshare)?
thanks

tools/shareworkbook
and uncheck the allow changes by more than one user box.
if it's in use make sure all people sharing have saved changes before you unshare or their data will disappear