APEX

Hi I am new to APEX. We have Oraclw 10.2.0.4 and APEX 3.2.

I have a field that I want to diplay a name of the person updating the record. I need to query a table to get it, as seen below. On my update form I wrote this in the SOURCE section :

select last_name||','||first_name display_value, employee_sys_id return_value from dba
where upper(peoplesoft_id) = :APP_USER

Source Type = SQL Querry

I want to display the last_name , First name on the screen but I want to record the employee_sys_id in the table. The query is returning nothing. When I replace te :APP_USER with the hardcoded user id that I am logged in with (which is a peoplesoft id) it works.

So for some reason :APP_USER is not getting the user id. I would appreciate some help.