This is the link where i am getting error from server.php file.
I got an error `Warning: socket_bind(): unable to bind address [98]: Address already in use in /opt/lampp/htdocs/wheel/server.php on line 12 Could not bind to socket Address already in use
That error means there's something already listening on that port you're trying to listen on.
To find the culprit, use:
netstat -tulpn
Then, after you made very sure you want to kill it, kill it, with either
kill $PID
or, if that doesn't work, use the crowbar:
kill -9 $PID
(replace $PID with the process id you want to kill)
some further information: http://www.cyberciti.biz/faq/what-process-has-open-linux-port/