Read() function is not workin in my dial plan

I created dial plan like this

exten => 8880,1,Wait(2)
exten => 8880,2,Answer()
exten => 8880,3,Read(USERID,/tmp/client/sounds/enter_userID,4,1)
exten => 8880,4,SayDigits(${USERID})
exten => 8880,5,Hangup

Read() function is not reading DTMF value.

please let me know if any body knows

Turn on debugging and see if you see the DTMF coming in to asterisk at all.

Are you using SIP?

SIP eats DTMF.