Help!! Password protected

Hi

I've got a copy of the spreadsheet I want to open in
zoho\zohosheet\users\username\spreadsheet.xls

But I'm being asked for a password to open it - I never set a password.

The local version is more up to date because I made a lot of changes without internet access.

How do I open it? Whats the password? Do I need to do a sych or something?

Thanks

Russ