EBS R12 Custom Form to add search Query

 https://www.youtube.com/watch?v=hLP4fGmy4Bc (check from 9min)
https://erpschools.com/erps/forms/query_find-form-in-oracle-apps
1. open APPSTAND.fmb form.
2. from object_groups drag QUERY_FIND to your form module(name of your custom form) and drop with ctl key pressed,
  once asked for confirmation select sub-class.
3. new QUERY_FIND OBJECTs will be created with same name under DataBlocks, Canvases, Object Groups of your custom form.
4. QUERY_FIND data block
Button New
replace the code with your block ex: DEPT
app_find.new('DEPT');
5. Button Find
:parameter.g_query_find := 'TRUE';
app_find.find('DEPT');
:parameter.g_query_find := 'FALSE';
6. open the canvas QUERY_FIND
drag one text field and give name ex: EMP_NUMBER_Q
7. Drag Trigger named QUERY_FIND from Appstand.fmb (STANDARD_OBJECTS) from main triggers section
and drop it to under your block ex: DEPT
8. open the code of this trigger we just dropped, modify it
--APPS_STANDARD.EVENT('QUERY_FIND'); --comment this
app_find.query_find('DEPT_WIND', --your main block window
'QUERY_FIND',
'QUERY_FIND');
9. under DEPT block new trigger pre-query:
if :parameter.g_query_find = 'TRUE' then
copy(:QUERY_FIND.EMP_NUMBER_Q,'DEPT.EMPNO');
:parameter.g_query_find := 'TRUE';
end if;