Try this
;Artificial Intelligence Script
;Conjured Header
desc = Music Fade
;Triggers
:state=0:music=audiobank\music\generic\main.wav,musicvolume=0,state=1
:state=1,plrdistfurther=500:musicvolume=0
:state=1,plrdistwithin=499:music=audiobank\music\ww2\incident.wav,musicvolume=10,state=2
:state=2,plrdistfurther=500:state=0
:state=2,plrdistwithin=449:musicvolume=20
:state=2,plrdistwithin=399:musicvolume=30
:state=2,plrdistwithin=349:musicvolume=40
:state=2,plrdistwithin=299:musicvolume=50
:state=2,plrdistwithin=249:musicvolume=60
:state=2,plrdistwithin=199:musicvolume=70
:state=2,plrdistwithin=149:musicvolume=80
:state=2,plrdistwithin=99:musicvolume=90
;End of Script
and feel free to modify it to suit your needs.
