subprocess.Popen("/home/lookyweb/message.js")
That file isn't executable because it doesn't have a shebang so that won't do anything. Try this subprocess.Popen("/usr/bin/node /home/lookyweb/message.js")
Also
if 'message.js'.encode('utf-8') in line:
this won't do anything either because the executable will be "node" and the arguement passed to the node executable will be "message.js". You can't kill a process based on its argument like that. So try this
if 'node'.encode('utf-8') in line: