Hi ,
I think i have got the reply.I am mentioning it hre so that it can be helful to others too.
Make new role and user.Now for security purpose assign this new role and ROLE_USER to the user and the folder where u wanna to apply the security make ROLE_USER to NO ACCESS and use another role to do the work like READ ONLY or ADMIN.. or whatever you want....
Actually , all users need at least ROLE_USER or ROLE_ADMINISTRATOR roles in order to log in and select menu options etc.
