I think this is a rather rude response to this question. Last Thursday I lost 45 minutes work because I closed the edit page I was working on, then realised immediately that I had not saved my work.
A reminder in the edit section such as "Have you saved your work?" or "Are you sure you want to close without saving?" when you try to close would save HOURS and HOURS of teacher time!!!!!!!
I'm not sure there's much you can do other than try to remember to save your work frequently. I don't think Bente Olsen was being rude so much as merely stating the realities of using Moodle. You simply have to save your work often.
I believe (and someone with more Moodle knowledge may help here) that there is a time-limit built into Moodle, and that if it doesn't see you doing something active (like moving between pages, saving work, etc.), it assumes you're not there and times you out. Unfortunately, typing within the editor doesn't register as activity, and so if you type for more than 15 minutes you'll time out and lose your work.
There is a little workaround that I use, which has saved my bacon on a couple of occasions.
If I think I've gone over the time-out limit, I select all of my text, images, etc. (control-A in Windows, command-A in Mac) and copy (control-C in Windows, command-C in Mac) before I hit the save button. That way, if you do happen to lose your work, you only have to open up the editor, paste your work back in (control-V in Windows, command-V in Mac), and hit save again.
I hope that helps! Meanwhile, there may be a way to extend the time-out period, but I'll have to leave that to more tech-savvy Moodlers.
Site Admin > Server > Session Handling > Timeout
The default is 2 hours in 1.9.4
However, that's not Elizabeth's problem. Her problem is not remembering to save before closing the editor. I believe we all remember & feel her pain.
Don't some browsers allow you to set an option to ask if you're sure you want to close a tab? Maybe this would be useful.
Never lose anything you type into a web form again! Lazarus securely auto-saves all forms as you type, so after a crash, server timeout, or whatever, you can go back to the form, right click, "recover form", and breathe a sigh of relief.
+1 with Ben. I have installed the Lazarus addon on my firefox browser and it's a real life-saver.