newbie to Nagios and cant use this plugin

Hello gurus,
please help a newbie with steps, here is what i did
*command.cfg*
define command{
command_name check_bw.sh
command_line $USER1$/check_bw.sh
}
*also here switches.cfg*
}
define service{
use generic-service ; Inherit values from a template
host_name SWC-AGG-01
service_description Bandwidth [RDD Backbone]
check_command check_bw.sh! -H 10.3.0.206 -b 100 -v 1 -C afm -m output -i gi10 -p 15
}
*see my result*
(No output returned from plugin)

*but it works when i run it in the terminal*
nagios/libexec# ./check_bw.sh -H 10.3.0.206 -b 100 -v 1 -C afm -m output -i gi9 -p 15
Current output bandwidth usage is 0 Mb/s, 0% used

what could be wrong?