Well, installing Joomla using a script? You have to install the script first and then follow the steps in the script and furthermore you install joomla later on. Rather it would be a good idea to install it yourself or let me know if you need any paid assistance.. You just have to upload the files and create a database thats all..
i know sir how to install it by myself, but i want to create free joomla hosting website and i want my website members to able to setup their joomla websites
Well, If you have Fantastico on your webserver, as in you are a VPS owner or a Dedicated server owner and you have Access to Fantastico, you shall want to play around with it so you can make it installed automatically.
If you have fantastico or HELM Application Packs or Elefante script installer available on your web server then it is possible to install joomla automatically.
But don't install via fantastico there are usually outdated versions of the scripts with bugs and security holes.