please tell me anyone how to install LAMP in linux i don't know the admin password,
while i am trying to install it, i am getting a error like

mkdir /usr/local/apache2
mkdir: cannot create directory `/usr/local/apache2': Permission denied

and also tell me how install using password.

you can only install lampp on su (admin root)

the username is root at http://localhost
no password
proFTP username is: nobody password is lampp
at ftp://localhost:21

once in lampp control panel you can setup the sql security and apache security

ensure that you are running
/opt/lampp/lampp start