It's ok. Not everyone can be *all knowing and powerful* like me. :lol:
When your bike was delivered brand spanking new, it came with an extra 3rd lock for the optional topcase. The dealer would have assembled your sidebags and installed two of the locks, and if you didn't order the Yamaha topcase to have upon delivery, they should have given you the third extra lock with the FJR. Usually in the underseat compartment or in a plastic bag with the owner's manual.
If they were fucktards and didn't provide you that third lock, or you bought the bike used and the original owner didn't give it to you, then you need to purchase your own. Of course you can go to a Yamaha dealer and have them order the $$$$ lock, or better yet, go to an online discount parts vendor like www.cyclepartswarehouse.com and order one yourself for much cheaper (along with spare fasteners, oil filters, air filters, yadda, yadda, yadda....) Or BEST yet, put an ad in the WANTED section of the forum. You can probably score one fairly cheaply there. There is usually someone around who has one they don't really need.
Good new/bad news: A competent locksmith should be able to re-key whatever lock you purchase to your own keys, but it will probably cost you a fair penny.