I am using this tag for my user authentication proxy server. and its work good. but I have a problem. because when i give user account using htpasswd. that user account can login multiple times to have internet access in deffirent computer.

What I want is if the user account is being use and the another user is going to use the same account it will be denied because the account is already being used. is there a way to do it? or script that should i read? or tags that i need to add in my squid.conf please kindly help me.. thank you very much...

auth_param basic program /usr/lib/squid/ncsa_auth /etc/squid/students
auth_param basic children 500
auth_param basic realm LA Proxy Server
auth_param basic credentialsttl 4 hours
auth_param blankpassword off
acl students proxy_auth REQUIRED
http_access allow students