10: the key is in the generated source. 20: enter a non-integer into form field and submit. the key is in the resulting traceback. 30: change the value in the GET request to a non-integer. the key is in the resulting traceback. 40: change the value in the POST request to a non-integer. the key is in the resulting traceback. 50: change the quantity value (hidden form field) to something greater than the stated quantity limit. the key is in the resulting traceback. entering non- integers is caught and handled, so that no longer works. 60: the key is in the cookie. note the javascript that reads a value from the cookie, hopefully causing the player to take a look at the cookie. 70: modify the cookie's content_name field to something invalid, reload the page and the key will be printed on the page.