[tex-live] question about a problem using TeX-Live

[Szisz Daniel]

Dear TeXnicians!

I've just installed the brand new TeX-Live system on my PC, and
have tried to install some more packages using tlmgr, but I got
the message

Updates for tlmgr itself are present.
===============================================================================
Please update the package manager first, via either
   tlmgr update --self
...

and so and I performed the update  command but immediately I got the 
answer

tlmgr: package repository 
http://dante.ctan.org/tex-archive/systems/texlive/tlnet
tlmgr: saving backups to /usr/local/texlive/2010/tlpkg/backups
/usr/local/texlive/2010/bin/i386-linux/tlmgr: 
create(tlpkg/tlpobj/texlive.infra.tlpobj) failed: Permission denied at 
/usr/local/texlive/2010/tlpkg/TeXLive/TLPOBJ.pm line 582

Can anyone help me in giving a hint how to recover and overcome this 
problem?

My address is orlando at caesar.elte.hu

Thanks is advance. Daniel Sz.