Dear all, could any kind heart person help me ? I need Record incoming call (from PSTN) with this format : YYYYMMDD-hhmmss-Agent ID, e.g: 20070511-11:59:40-AgentID6004
Thank you… 
it is working, thank you very much for you kindness. After 2 weeks of trying, and now I can do it.
May other friends want to know my code ? Here we go…
[6004] ;extensions.conf
exten => 6004,1,Answer
exten => 6004,2,NoOp(${CALLERID(all)})
exten => 6004,3,Set(CALLERID(all)=agentsam)
exten => 6004,4,NoOp(${CALLERID(all)})
exten => 6004,5,MixMonitor(/usr/local/src/${STRFTIME(${EPOCH},%Y%m%d-%H%M%S)}$(CALLERID(all)}.gsm)
exten => 6004,6,Dial(SIP/6004)
Hope above code help you all, when you are frustrated.