Ubuntu :: Not Getting Background Daemon Statup Service Notification Message Box

I have created a script named ssh_inotify.sh to check /var/log/auth.log log file for newly started ssh session and display a question message box. This script uses inotifywait to monitor this above log file for modify file event and zenity to create question message boxes.Now i have created a startup service config file named ssh_inotify under /etc/init.d folder and placed the script ssh_inotify.sh under /usr/sbin and chmod this script to be executable.

The service config file ssh_inotify uses start-stop-daemon to run this script as background process.Now theproblem is that when i start this service using sudo service ssh_inotify start, the service is started, I can confirm this using ps -A | grep ssh_inotify also i can check for the PID associated with it under /var/run/ssh_inotify.pid. Now when i ssh to my machine, i do not get the question message box, I am writing in log file and in that i can see that the message under cancel button option for question message box is getting printed.This script runs perfectly when run directly or using start-stop-daemon command directly (exact command as typed in service config file above) on terminal, but not when this same command is executed using service file.Can someone please suggest me the solution and reason for such behavior when same command executed under different mode (using service or directly from terminal).If you guys require code, i can attach the files (currently i am in office so don't have access to these files.)