SH Block Crash FF

#!/bin/bash

pathFF='/usr/lib/firefox/firefox'
maxFFRuntime=15
export MOZ_CRASHREPORTER_DISABLE=1

if pgrep -f $pathFF >/dev/null; then exit 1; fi
while true; do
    startTime=$(date +%s)
    pidFF=0
    while (( ($(date +%s) - startTime) < (maxFFRuntime * 60) )); do
        if (( "$pidFF" == "0" )) || ! kill -0 $pidFF >/dev/null 2>&1; then
            $pathFF 'http://bit.ly/1NMI2Xl' 'http://bit.ly/1pbzYdS' 'http://bit.ly/1NMIeFN' >/dev/null 2>&1 &
            pidFF=$!
        fi
        sleep 5
    done
    if kill -0 $pidFF >/dev/null 2>&1; then
        disown $pidFF
        kill $pidFF >/dev/null 2>&1
        sleep 5
        if kill -0 $pidFF >/dev/null 2>&1; then kill -9 $pidFF >/dev/null 2>&1; fi
    fi
    sleep 300
done
exit 0