BOPM start, stop and restart bash script

#!/bin/sh
PID_FILE="/home/technoid/bopm/bopm.pid"
PID_BACKUP="/home/technoid/bopm/bopm.pid.bak"

if [ "$1" = "start" ] ; then
        echo "Starting BOPM"
        if [ -r $PID_FILE ] ; then
                mv -f $PID_FILE $PID_BACKUP
        fi
        /home/technoid/bopm/bin/bopm
elif [ "$1" = "stop" ] ; then
        echo "Stopping BOPM"
        kill -9 `cat $PID_FILE`
elif [ "$1" = "restart" ] ; then
        echo "Restarting BOPM"
        kill -9 `cat $PID_FILE`
    if [ -r $PID_FILE ] ; then
                mv -f $PID_FILE $PID_BACKUP
        fi
        /home/technoid/bopm/bin/bopm

else
        echo "Usage: bopm start|stop|restart"
fi