parental control dsi

What is the master key to the ISD for parental control?
I have a DSI for Christmas, but I can not buy games any cause apparently no blocking of her parents, of course, I do not know. I will not solicit support for the cause of the 1 key (all at home now. 2 (I do not really agree that people can not come to understand most of the time. So if anyone knows please really appreciate it. ten points to who gives me
Are you connected to the Internet, because their parents could have blocked some sites.
Nintendo DSi United Kingdom Tutorial 4 – parental controls