You can save a note (control S or manual file save). It will go to your inbox.
Deleted noted are in the deleted section of the message box, scroll down to the bottom. If you accidently delete something you can retrieve it.
I agree with Bert, (or is it uhmarika?) I have not lost a chart in the last 9 years. I have had to retrieve a few though.
I finish charts in the room 95% of the time. I will sometimes delay on a chart where I want to do more extensive verbage. These are always completed in a few days so billing can be done.
Many times I get a message on "clean" charts asking if I want to close them. I always get the message if I have made changes.