Show/hide based on Multiple selections in a select box

Question

In my http header I have the following code...
it works great as long as only one value is selected:
if you highlight the ARRAMO value the DUNS field appears...
if you highlight anything else the DUNS field disappears...
but if I highlight both ARRAMO and another field, I want the DUNS to SHOW and it DOESNT..
how do I fix this?
<script type="text/javascript" src="#WORKSPACE_IMAGES#jquery-1.3.2.min.js"></script>
<script language="JavaScript" type="text/javascript">
<!--
htmldb_delete_message='"DELETE_CONFIRM_MSG"';
//-->
</script>
<script type="text/javascript">
$(document).ready(function(){
$('#P1_DUNS_NUMBER').attr("disabled", true);
$('label[for=P1_DUNS_NUMBER],#P1_DUNS_NUMBER').hide();
$('#P1_APP_REQUESTED').change(function(){
if($(this).val() == 'ARRAMO'){
$('#P1_DUNS_NUMBER').attr("disabled", false);
$('label[for=P1_DUNS_NUMBER],#P1_DUNS_NUMBER').show();
}else{
$('#P1_DUNS_NUMBER').attr("disabled", true);
$('label[for=P1_DUNS_NUMBER],#P1_DUNS_NUMBER').hide();
</script>

Answer 1

Using LOV, you can have multiple selection.
For this you can write code in the KEY-LISTVAL trigger.
Create an LOV for store code.
In the text-item of store_code (where you want mul. selection), you assign the LOV to that item.
In key-listval trigger,
You can have something like
Declare
m_val varchar2(1000);
a boolean;
Begin
m_val := :store_code;
a := show_lov('STORE_LOV');
if a then
  If m_val is null then
     m_val := :store_code;
  else
      If instr(','||m_val||',' ,||','||:store_code||',') = 0   /*check whether store code already selected, to get excat string comma is concatenated*/
         m_val := m_val||','||:store_code;
      end if;
  end if;
end if;
:store_code := m_val;
End;Note :To check for validation, additional coding is required...