Save Options Grayed Out

Hi, I'm a relatively new user to Corel so please excuse my ignorance.  I was working happily on a booklet in Corel until 2 days ago it grayed out all of my "save" options.  Both in the drop down menu and on the shortcuts list!  I'm really worried I might loose 2 days worth of work due to this!  Any ideas on how I can get this back?  I can't even use Save-As.   I have no idea why it suddenly stopped letting me save my work.