asterisk users - Jan 2005 - ChanIsAvail + Zap and SIP channels

Hi,

if user is talking with Zap/1-1, ChanIsAvail(Zap/1) return Zap/1-2.
Is there function which returns 1 if user talking (and work with Zap and SIP
channels) and returns 0 when channel is idle?

Thanks

Jan Jirasko