Losing info on review before finishing

I am new to this but on two different occasions while completing a review, I inadvertently hit a key that took me out of the review and I could not find what I had been working on. If you accidently leave the review and are taken to another page, do you lose what you have completed or is there a draft of what you have done somewhere. I guess I need to be more careful.
No draft. Just hit the back button in your browser. Your work should be there. Also you can use the File Menu option to Save File from the browser Menu bar. Save as Complete Web Page. You can continue to Save as you work. But depending on the Time lapse you may have to Start A New Review in another Tab and then copy and paste from your Saved copy when you go to publish the Review.
thanx