Oracle Web Form Problem

I'm in desparate need of web forms help. Below is a description of my problem.

Scenario: I have a web form that allow users to retrieve records from the database. So far all the fields on this form are poplists.

Problem: I don't know how to dynamically populate values in one poplist based on the value selected in another poplist. Below are examples the cursors and the code used to build the poplist fields.

 cursor curs_org_abrv_name is
  select abbreviation, id from external_organizations   order by abbreviation;

 cursor curs_org_name (abbrv_in VARCHAR2) is   select name, id from external_organizations   where orglevl_id2 = abbrv_in
  order by name;

• Code for first field. Value here should be passed to second field

  ---

htp.bold( 'External Organization Abbreviation:');  htp.formSelectOpen( cname => 'ext_org_abrv_name_lov' );  for crec in curs_org_abrv_name loop
  htp.formSelectOption( crec.abbreviation,

             cattributes => 'VALUE="' || crec.orglevl_id2 ||'"');  end loop;
 htp.formSelectOption( '    ',

            cselected => 'TRUE', cattributes => ' VALUE="0"');  htp.formSelectClose;
 htp.bold( htf.anchor(
'http://mapping.usgs.gov/internal/acis/agrmhelp.html#ext_org_name',
'Help'));

 htp.br;

• Code for second field. This field should be populated based on the value chosen in the first field -------

 htp.bold( 'External Organization Name:');  htp.formSelectOpen( cname => 'ext_org_name_lov' );  for crec in curs_org_name loop
  htp.formSelectOption( crec.name,

             cattributes => 'VALUE="' || crec.id ||'"');  end loop;
 htp.formSelectOption( '    ',

            cselected => 'TRUE', cattributes => ' VALUE="0"');  htp.formSelectClose; Received on Thu Oct 22 1998 - 00:00:00 CDT