[Users] cancelling INVITE during OK response

hi, is there a way to cancel or terminate an INVITE or call upon receipt of the OK reply. my configuration invokes an external program which either return success or failure for OK message (response to INVITE). when failure is returned, i want the script to terminate the call or cancel the INVITE (OK message will not be forwarded to the calling UA). is there an existing function or module to realize this? the scenario is drawn below with provisional messages removed. UAC1 ------------------ proxy1 ----------------- proxy2 --------------- UAC2 call: INVITE ---------------------------> INVITE ----------------------> INVITE -----------------> OK <---------------- *XXX - error occurred during processing OK message thanks, sho --------------------------------- It's here! Your new message! Get new email alerts with the free Yahoo! Toolbar.