[SR-Users] Subst_body M Audio

Hello, I'm trying to replace the M part in the SDP Body. Seems not working as expected ( I changed the "s" part without problems ) Code : if ( subst_body('/(^m=.*)/m=testing of rewrite.\r/') ) { $var(s)=""; }; Here's the incoming body message c=IN IP4 217.112.180.235. t=0 0. m=audio 49152 RTP/AVP 8 9 18 101. a=rtpmap:8 PCMA/8000. a=rtpmap:9 G722/8000. a=rtpmap:18 G729/8000. a=fmtp:18 annexb=no. a=rtpmap:101 telephone-event/8000. a=fmtp:101 0-15. After subst. ( note the .10840 on the m line) c=IN IP4 217.112.180.10. t=0 0. m=testing of rewrite..10840 a=rtpmap:8 PCMA/8000. a=rtpmap:9 G722/8000. a=rtpmap:101 telephone-event/8000. a=fmtp:101 0-15. a=nortpproxy:yes.