Populate one text field on a form based on the value in another

Question

I am new to APEX and building my first application.
When a user enters a value in one field, I would like to run a SQL command and then display a value in another field based on the value in the first field. For instance, if a user enters a part number in one field, when they tab off of the field, I would like to display the name of the part in the part name field.
Thanks

Answer 1

Thanks. That put me on the right track. I used that link to find the link http://htmldb.oracle.com/pls/otn/f?p=11933:11:2890374750690437 and then using the two was able to put together a solution.
I am down to one last issue. I am able to return the name back from the process and display it with an alert statement. Unfortunately, I am unable to display the value on the form.
I am doing the following.
<script language="JavaScript1.1" type="text/javascript">
function f_getCustomerName(id)
var v_id = id;
var get = new htmldb_Get(null,$v('pFlowId'),'APPLICATION_PROCESS=getCustomerName',$v('pFlowStepId'));
get.addParam('x01',$v('P2_CUSTOMER_ID'));
gReturn = get.get();
get = null;
gReturn = (!gReturn)?'null':gReturn;
/* The below do not work
$s('P2_CUSTOMER_NAME',gReturn);
document.getElementById('P2_CUSTOMER_NAME').value = gReturn;
document.getElementById('P2_CUSTOMER_NAME').value = 'TEST';
alert(document.getElementById('P2_CUSTOMER_NAME').value );
alert(gReturn);
//-->
</script>
Process: getCustomerName
declare
l_customer_id customer.customer_id%type;
l_customer_name customer.customer_name%type;
begin
l_customer_id := to_number(wwv_flow.g_x01);
select customer_name
into l_customer_name
from customer
where customer_id = l_customer_id;
htp.p(l_customer_name);
end;