Welcome to my third XSS challenge!
This Challenge is the "difficult version" of XSS Challenge #1
The only difference between XSS Challenge #1 that XSS Challenge #3 has X-Frame-Options set to Deny, while XSS Challenge #1 is not.
This challenge's goal is to execute an alert() on this page, by following the rules.
X-Frame-Options has been set to Deny, to make the challenge more realistic to live web-applications.