RFID based security/attendance system

sir its me again,
u have updated attendance system ckt but wat abut the security system ckt,is it the same,if it is wat are A,B,C,D?
please sir could u explain the whole circuit of RFID security system 2 me,coz this is for my last year project..
i will be very grateful to u...
thanx for the previous reply sir....

i need to analyse the code for this. as its no my project so explaining it will take time.so you have to wait.

ok sir,
could u then explain 2 me the CALLER ID project,i noe its from the same author,but still.........

thanx again

sure i have already gone through that project so wont be any problem explaining it can you create a new topic for that project. so it will be easy to sort for others.