Already Did
Unfortunately unless you do, you can give up XSS. Because 90% of it is just that.
I Don't Know Jack Shit About Page Coding
Learn how to build an FLP from raw data. Aka go to Welcome to Gaia | Gaia Online copy the source and build an FLP. When you accomplish that try moving on. Remember that the first step to hacking is making a hack, you need to pre-pare yourself for that task.
I'm Trying To Move Up From Just An FLP User To Something Better >.<
Adding to what Personoid said, it isn't if it is possible, it is how could it be possible. See XSS is a type of injection, for an injection trk you need to have a way to inject the malicious script. FLW's are XSS, they are sending scripts through images to gaiaonline. Gaiaonline attempted to stop it by adding Whitelisting, but it is still possible. Commonly people mistake XSS as pure JavaScript injections, which is false. It also includes SQL Injection, SWF Injection, CSS Injection, and Image Injection.
