How I can block some site?

[josephchoi]

I want to block www.4shared.com, so that I add to always block list. But, it does not work after 3 minutes. 
Can you help me?

[rotblitz]

If you want changes to take effect immediately, you must flush your caches.

https://support.opendns.com/entries/26336865-Clearing-the-DNS-Cache-on-Computers-Servers-and-Web-Browsers

Also, unless you want to block only www.4shared.com, you better block 4shared.com which covers this and all subdomains like www.

[josephchoi]

Thank you for adviser. But, it did not work.

Could you try it with www.4shared.com through your computer?

[rotblitz]

Your problem may be of a different nature then.  Post the complete plain text output of the following diagnostic command:

nslookup -type=txt debug.opendns.com.