You can get your pin number by going back to the main screen and looking at the left hand column for the link there that mentions PIN in its description. Click on that link and you can then receive a new PIN number and then go back to the submission screen, enter it, and you are done. Be certain to print out your proof of filing and keep track of your user name and password for next year. This handy hint may save you 40 minutes or more waiting on the help line for them to explain to you that the website is not correct and then tell you where to find the PIN number.
The link to register to file your FBAR on line is at: http://bsaefiling.fincen.treas.gov/Enroll_Individual.html
After June, paper form filings will not be allowed. If you try to file on paper, your form must arrive by 6/28/13. Unlike tax forms, date of postmark does not count!