Problem with proxy?

[Guest Quba]

Hi everyone, I have a problem with connecting to internet by squid

proxy server. While I'am trying to log in to proxy, after confirming

the authorization the web isn't starting. It's just view a message:

"Url could not be retrieved, access denied, contact to your proxy

admin". I'm wondering is solution of the problem on terminal (maybe

some application blocked some ports) or on proxy side (admin disabled

access from this end-terminal). I especially turn this question to

admins, please help.