How to check if an extension has follow-me config settings


I am testing follow-me features on Asterisk 1.6.0.

Here’s some snippet of my followme.conf:

Here’s some snippet of my extensions.conf:
exten => _ZX, 1, Dial(SIP/${EXTEN},20)
exten => _ZX, n, GotoIf($["${DIALSTATUS}" = “BUSY”]?busy:unavail)
exten => _ZX, n(unavail), FollowMe(${EXTEN})
exten => _ZX, n, GotoIf($["${DIALSTATUS}" = “BUSY”]?busy:unavail2)
exten => _ZX, n, Hangup()
exten => _ZX, n(unavail2), Voicemail(${EXTEN}@default, u)
exten => _ZX, n, Hangup()
exten => _ZX, n(busy), VoiceMail(${EXTEN}@default, b)
exten => _ZX, n, Hangup()

I noticed that if an extension doesn’t have follow-me settings, the call will go into infinite loop according to the dial plan above. How can I check if an extension has follow-me settings? What is the recommended way of checking this?

Never mind. I made some mistake in my tests.