Running bash script in upstart .conf script

I would like run my bash script (kvm_manage) in startup, and it doesnt work. Here is my upstart .conf script:

      description "kvm start skript"

      start on local-filesystem
      stop on shutdown

      respawn 

      script
         exec /etc/kvm_manage start
      end script

I want run it with argument "start". It is possible? What should I change?

thanks for help