If you can't get it, go to this link and someone will be able to do it for you.
http://www.pitbulltalk.com/viewtopic.php?t=114
The site Joyce linked to is really simple, just upload your pic, change the size to 100 and then is should fix your pic for you. Right click on the pic, and save it to your computer. Afterwards go to your profile, select browse, find your pic, and wa la. (Much easier after the first go round, of course!)