I cannot create new folder inside /opt directory

[subakaran]

Hi ,all
am new in ubuntu.
I have Administrator rights.
I want to create new folder into /opt directory.
So i clicked(Right click). but new folder menu has disabled. I cannot create new folder.

Then Alternatively I used terminal. then I type mkdir /opt/lampp/htdocs/dummy
now folder name has created. but I cannot paste anything into my dummy folder.
So I checked permission which has you are not owner.

Please advice to me.
How to create new folder & copy contents to new folder.
please.
Thanks.

[oldos2er]

Either use "sudo" in the terminal, e.g.
sudo mkdir /opt/foo or run
gksu nautilus to open Nautilus with admin privileges.