The author field isn't editable after uploading a synth. That's something of a different discussion, though.
If you want your own name listed next to a photo, you should enter the appropriate photographer's name into the metadata of each photo.
This is considered the absolute basics of digital photography if you've taken even an introductory class at college in digital images. Fill in the metadata for Photographer or Author field (different programs name it slightly differently) and the Copyright field. This is so that in the case that someone uses your image without your permission you will have some evidence that it is yours (unless the thief also knows about metadata and has wiped it out =).
In any case, if you have Adobe Bridge, Windows Live Photo Gallery, Microsoft Pro Photo Tools, etc., etc. then you can easily do this. For that matter, you can also edit this from Windows Explorer in Windows Vista and Windows 7 (and in XP, if you have the right plugins).