I noticed when sending private messages, we can save our replies in the outbox of which I have checked.  Now, how does one open their outbox to see what they wrote (working on a story with a friend)?

[To-Get-Her]

1) Sign in
2) click on the "My Messages" on the  line over your information box
3) on the left hand side there's a box saying "Messages" go to the third item down "Sent messages" and click on it
4) find the message that corresponds to the message you are looking for  and once more click on it

Don't close unless your done with it!
Now to continue writing from there you will have to start a new page and send a new message.

Personally i would suggest using Google Docs or Microsoft Word to write your story then paste, edit and send to your friend. Make finding, continuing it so much easier!