The easiest way to post a gift story to the Archive of Our Own is to use the “Assignments” page. You can find a link to your Assignments page on your dashboard. (Go to your profile and look at the column on the left. It does have the link to all your challenge assignments in the lower sections.)
On this page you will see a list of all your assignments. In this case look for “Public Call - Doctor Who fic exchange 2013” for [name of recipient]. To the right you'll see two buttons saying “Fulfill” and “Default”. To post your story click the “Fulfill” button and it will automatically fill out the posting form with the correct collection, assignment and recipient tag.
The system can only recognize one posted story as your official entry to the exchange, but it's possible to write and post more than one story for your recipient. If you want to post another story after your assignment was fulfilled, simply open the posting form and under “Associations” put in the relevant information like the correct collection name (Public Call - Doctor Who fic exchange 2013) and write the name of your recipient into the “Gift this work to” field.
Once you've uploaded, you can continue editing until the collection is closed to entires. We ask you not to upload unfinished stories.
If you run into any trouble, let us know!