Application Express :: Second LOV Data Depends On Selected Data Of First LOV?

In my page, I have two items(type Popup LOV): P2_APP and P2_MOD and I've created two LOVs for each item. What I want is that when I select one value in first LOV in second LOV I'll get data that is related with select value in first LOV.

My table logic in database is ok, and select statements are alright.

I think that select statement in second LOV is not fetching data from first LOV item:

select MOD_NAME as display_value, MOD_CODE as return_value
from MODS
where APPLICATION= *:P2_APP* <-------- this is first LOV item with data previously selected
order by 1