How to make the user list view not editable by the users.?

My requirement is, user list view should not be editable by any sales user and only the row respective to the sales user should be shown. admin should be only person who should be given write access to the users list.
Any inputs on this would be really helpful.

http://frappe.github.io/erpnext/user/manual/en/setting-up/users-and-permissions/

i read through this and did exactly as told, but for some reason doesnt work on user list. The user is still being able to edit even when he has only read access.

i guess User is a core frappe module.

May be Role assigned to the user,permits him to write,check Role Permission Manager

i did check, there was no role linking to user and the role i have assigned to him.

By default,his row only visible to every user except administrator

True, and what do i to make it non editable by the user and only by the administrator??