Grading a dropbox

I found using the Turnitin.com plagiarism detection service to have a nice side effect when grading. I can navigate among submissions within the Turnitin.com interface, which already opens in a new browser window. So I can open an originality report in one window and open the feedback page for that student in another window. This makes it important for students to include their names as part of the filename or somewhere in the text of the paper so I can easily identify whose paper is in the Turnitin.com window. Turnitin.com assigns a user number  but there is no easy way (if any) to match that to the student ID number or name.