[Freeswitch-users] Use lua to replace a .wav file

Hi, I am using freeswitch as call announcement purpose. Admin user can call in and record a sound clip and then updated the announcement sound clip. I created IVR menu and use the recording lua to record the sound clip (to record as temp...uuid...wav file). It is ok. However, I do not know how to replace the announcement sound clip after the user press a key in ivr to confirm update. I try to use lua to do it, but it seems that it do not have file replacement function. Am I correct? Thanks Raymond