sorting a listing page

Hi
    I have a list page for users. I am using will_paginate for
pagination. So an example is

full_name(f_name+l_name) email unit(this an integer colum is
user.buildng.unit)

Clinton Trone cliff@test.com 2
Evette Pace evet@test.com 2
Brett B brett@test.com 10
...............

         My requirement is to sort by any of the headings ie
first_name, email or unit on clicking them. Also I need Alphabetical
sorting .Like there will be
All,A,B,C ...Z,Other
   in the list page. Then on clicking suppose D the paginated list has
to sorted by letter 'D' like that. I have no idea how to implement this.
Please help

Thanks in advance
Tom

Hi
   In short I am searching the best grid plug/gem in rails

Thanks
Tom

Hi
    I still could not get an exact choice. I found this
http://www.2dconcept.com/jquery-grid-rails-plugin

    But suppose if have a column like full_name but it is not a db
column ( i have db columns firstname and lastname) then what I will do?
If anybody has any other choice than please help.

Thanks
Tom