[jQuery] Help: Iterate through unknown number of elements, apply function

[xstaceyamayx]

Hey there, newbie here...

Still getting a grasp on jQuery, so I'm probably overthinking or extra-
typing...

Anyway, I have 2 select boxes. I can populate SelectA with items from
a database, move the items from selectA to selectB and back again by
clicking "add" and "remove"...
BASIC CODE (HTML):
<div>
  <select multiple id="selectA">
   <?php
        //populate with database information
        ?>
  </select>
  add >>
 </div>
 <div>
  <select multiple id="selectB"></select>
  << remove
</div>

(JQUERY):
$(document).ready(function(){
        $('#add').click(function() {
                return !$('#selectA
option:selected').remove().appendTo('#selectB');
        });
        $('#remove').click(function() {
                return !$('#selectB
option:selected').remove().appendTo('#selectA');
        });
});

THE ABOVE SITUATION WORKS...
What I want to do is generate a set of these "selects" for each
category in my database. I can do that through php and the use of a
counter.... I get "selectA_".$ctr, "selectB_".$ctr, add.$ctr, and
remove.$ctr as I should (i.e. first set of generated boxes would have
the elements: selectA_1, selectB_1, add1, and remove1). BUT I have to
add the click functions in the document ready function to this unknown
number of elements, so I'm trying my first jQuery each statement -
without any luck....

HERE IT IS.... sorry if I butchered it... #input4 is the name of the
form I have this scenario in...

$("#input4").find("select").each(function(i){

                var addButton = "#add"+i
                var selectA = "#selectA_"+i+ " option:selected";
                var B = "#selectB_"+i;
                $("'"+addButton+"'").click(function() {
                return !$("'"+selectA+ "'").remove().appendTo("'"+B
+"'");
                });

                var removeButton = "#remove"+i
                var selectB = "#selectB_"+i+ " option:selected";
                var A = "#selectA_"+i;
                $("'"+removeButton+"'").click(function() {
                return !$("'"+selectB+ "'").remove().appendTo("'"+A
+"'");
                });
        });


I'm a little lost at the moment and you could say overwhelmed. I just
need a little bump in the right direction to regain my "get up and
go."
Thanks in advance.