Originally Posted by mehreen
yes i want to set up ftp server in ubuntu box using vsftp and to show that how server upload the files, d0wnload and access it by using file zilla
You can follow this HOWTO
to set up VSFTP.
Have a look at the tutorial
Bear in mind that if you are behind a Router that does NATing (most users connect to the internet using one of these) and you want the ftp server to be available to the outside world then you will need to set up port forwarding in your router.
Also make sure that your ip address is static or notify your users when it changes, this is your external ip address by the way.