Dynamic action on text box change does not working

Question

i have a page with following components.
a report that has and edit link.
a text box to catch the primary key from report link when it is clicked
a number of elements (text boxes, check boxes and LOVs) which are used as data entry form.
Now my design is that user enter values save them and no sooner did they save, the report depicts new
values. if user want to edit any record, they click on edit link and the data entry form elements
should now bring all those values from DB on page. i m successful to pick primary key and bring
it in a hidden text box and wrote a dynamic action on its change event that will bring values from
DB and set all page elements. but but but.........the change event doesnt work. it only work
when focus is lost from the text box...!! offcourse user wont want to click in that "hiddent" text
box and then click some where else to bring values in page data entry form......
help is humbly requested from forum or if any other solution approach is to be used easier than
one i m using, would be appreciated.
thanks in advance for reading my bore question :)

Answer 1

bundles of thanks for reply. i m going to elaborate.
1. My page no is 3.
2. Hidden Item name is P3_EDIT_ACTIVITY_ID
3. Data entry form, hidden item and the report are on the same page.
4. on the edit link of report, i have used following settings.
    Target: Page in this application
     Page: 3
     and i set hidden item as follows......
     Item 1   P3_EDIT_ACTIVITY_ID         Value #ACTIVITY_ID#
   well, when i click the link on report it does bring Activity_Id in the hidden box (which is not yet hidden for debugging purpose)
Next i wrote Dynamic action which fires on the change event of P3_EDIT_ACTIVITY_ID and run PL/SQL code with in it which is as follows
  declare
  Dept varchar(50);
begin
   select my_dept into Dept from activity_main ACTIVITY_ID = :P3_EDIT_ACTIVITY_ID;
   :P3_Dept := :Dept;          (i did use :P3_Dept := Dept also but this wont work)
  insert into testdynamic (stamp) values (Dept);  (I did this to check whether correct value is brought from DB, yes it works correctly, correct Dept is being inserted in stamp column)
end;
  i have created another true action to check when the dynamic action is fired. its very simple alert. and the problem is, it only fires when focus is lost from the P3_EDIT_ACTIVITY_ID. i mean, when u keep changing value inside the text box, nothing happens, when u go outside, the alert is fired and so the pl/sql procedure. but the line
    :P3_Dept := :Dept;       OR      :P3_Dept  := Dept;         arent working which is the actual requirement.
  I m not using set value here as i have to set a lot of values on page not one. further. plz let me get rid of this lost focus thing as i want the form to be populated with correct values related to P3_EDIT_ACTIVITY_ID as the user click on any edit_link in the report.
Thanks for persistence. i hope i have provided all the details.
looking forward.