Almost all Debian derivations (and Ubuntu is one of them) use only the runlevels 0,1,2 and 6 by default. 0 and 6 are reserved for system shutdown and reboot, 1 is single user mode and 2 is the default multi-user mode with network and GUI (if you have a display manager installed). Runlevels 2-5 are available, but are the same. So please specify your question, what is it that you want to achieve?
By the way, your threads will draw more attention if you use thread-names resembling the topic of your thread. Just a "Plzz" will cause that many members will not be willing to look at your thread, especially if you use text-speak. Keep in mind, all of us are trying to help here in our free time, no one is paid. Why should we have a look at a thread if the poster isn't even making the effort to name it appropriately (and read the hints on the page for creating a new thread)?
Last edited by TobiSGD; 01-19-2012 at 12:02 PM.