I came to realize yesterday when I was working on a wiz and extremely fatigued that it's pretty easy to accidentally delete (and quickly hit the confirm button) the wrong capsule or if you copy paste and get distracted and forget to paste before copying a poster item number- blah- then your "safety net" is to open a preview of your article to keep open AS you edit and write it.
When I make a change and like it (or several small changes) I'll click over to that tab and simply refresh it. If you make a mistake that's permanent you can still copy it off that preview which isn't updated as you make changes but only when you refresh the page.
This saved me several times!
Jerrico
P.S.
Oh and if your using firefox browser (any version) there is an amazing plugin called Lazarus that records forms as well as any text or entry box on any page including what's typed into the text mod. This means if you do delete text from any form you can get it back by right clicking into the form and clicking on the entry that shows what you had (you will want to make sure you back up whatever else is in there first as it overwrites the whole thing (often with whatever is in there anyway but be safe)...
This has saved me numerous times.
You can find the plugin here:
https://addons.mozilla.org/en-US/firefox/addon/lazarus-form-recovery
or just clicking tools>add ons> search for "Lazarus" everything it records is incrypted