ANY WAY TO SEE IP ADDRESS WITH PROXY USER NAME

["Abhishek Chavan" <bezudar@xxxxxxxxx>]

I AM USING SQUID AS AN HTTP PROXY TO GIVE INTERNET ACCESS. PEOPLE GET
ACCESS BY USING A USER NAME AND PASSWORD GIVEN TO THEM . IS THERE ANY
WAY I CAN TRACE WHICH USER NAME PASSWORD IS BEING USED FROM WHICH IP
ADDRESS?