php - ceck client status

Hi, I'd like to wrie few php script to manage users sessions Are there any posibility to ask freeradius, like nas does it, about client status? some virutal servers which can answer? for example. I'd like to know if client bob is logged still? that i send to freeradius pacect acc-status-client=bob, and FR aswer yes or no. something in that way. -- Regards Marcin / nicraM