Hi, I don't know where to ask this question so I decide to ask it here. I search all over the web and cannot find the solution. I use mac system. The website i want to block is: "tankionline.com" I used the first method stated in this webpage (http://www.wikihow.com/Block-a-Website-in-Safari) which can block many websites successfully but particularly not "tankionline.com". I flushed the DNS many times and restarted my computer. Why is that? Thank you very much for any help and suggestion.