Trying to use set_value in onChange event handler

Question

Is it acceptable to use p_session.set_value in the onChange event handler?
I am trying to do a couple of things in this event handler, I am trying to validate a code and if the code is invalid I wish to
show an alert. If the code is valid I then wish to fill another field with a value from the database. Both fields I am working
with in the event handler are table columns. I have not been able to track down a specific error message, however, when
I view source the code for this is blinking. Here is what I am trying, in the onChange event handler.
declare
l_acct varchar2(21);
l_codeid number;
begin
l_acct := p_session.get_value
(p_block_name => 'DETAIL_BLOCK',
p_attribute_name => 'A_CONCATENATED_ACCT',
p_index => 1);
if l_acct is not null then
select code_combination_id
into l_codeid
from webapp1.an_code_combinations_v
where concatenated_acct = l_acct;
if sql%found then
p_session.set_value
(p_block_name => 'DETAIL_BLOCK',
p_attribute_name => 'A_CODE_COMBINATION_ID',
p_index => 1,
p_value => l_codeid);
else
--- how can I display an alert?????
end if;
end if;
end;
Any suggestions on how to show an alert, and how to display values into fields would be very helpful.

Answer 1

I think you are trying to use PL/SQL in the JAVASCRIPT onChange event handler. What you need to do is use JAVASCRIPT.
Put the following function on the (... before displaying the page) option on the Additional PL/SQL page.
Javascript function that loop through all fields on a form.
Set value Example:
htp.p('<script language = "JavaScript1.3">
function setCommValue(form,target,value)
var itemname;
for(var i = 0; i < form.length; i++)
itemname = form.elements.name.split(".");
if (itemname[2] == target)
form.elements[i].value = value;
</script>');
You can call the above code from a Javascript Event Handler for a Form item. Example: (an item's OnChange Event)
setCommValue(this.form,'SITE_ID',this.value);
Good Luck and let us know if you experience in Lessons Learned.
Thanks,
Linda Gowen