Lock Open Excel Document
 

When the excel spreadsheet is open, someone else will try to open it and they
get a message stating the document is opened by "whoever", but they can open
a read only copy. People are opening the read only version and making
changes and of course their changes are not saving. Is there a way to lock
an open excel document so noone else can open it until the person has closed
the document. Thanks for any help provided.