Using AJAX with ApEx

Question

Hi All,
I'm new to Ajax and I'm trying to create an alert that prompts the user if the information that they entered into a form results in a primary key violation. The problem is that the application procedure that I created is not returning a value when it should be, because I am not receiving the alert when I violate a primary key...I don't know what I am doing wrong. Any help would be much appreciated.
My javascript code is as follows:
function checkNull(){
var get = new htmldb_Get(null,&APP_ID.,'APPLICATION_PROCESS=P3PK',0);
get.add('P3_MEMIMPNUM',$x('P3_MEMIMPNUM').value);
get.add('P3_ACTIONDATE',$x('P3_ACTIONDATE').value);
get.add('P3_ACTION',$x('P3_ACTION').value);
ajaxresult = get.get();
if (ajaxresult)
alert("Primary Key Violation!");
get = null;
The application process P3PK is processed On Demand and the PL/SQL Block is as follows:
DECLARE
str_memimpnum varchar2(15);
BEGIN
SELECT memimpnum
INTO str_memimpnum
FROM tblaction
WHERE memimpnum = :P3_MEMIMPNUM AND
actiondate = :P3_ACTIONDATE AND
action = :P3_ACTION;
HTP.prn(str_memimpnum);
END;
Finally, the save button is set to redirect to a URL and the URL target is as follows:
javascript:onclick=checkNull();
Note: There is more to the checkNull function, but I only included the section that I felt was applicable to this issue.
Thanks in advance!

Answer 1

Hello,
Most likley it's an issue with your OnDemand Process.
Change your alert to
alert(ajaxresult);
And then in your process change it to with a htp.prn('Hello World'); to make sure your calling the right thing.
Then output the item values.
htp.prn(:P3_MEMIMPNUM);
Just work your way through it.
Also you can easily debug these returns using Firebug addon in Firefox. http://www.getfirebug.com
then
Regards,
Carl
blog : http://carlback.blogspot.com/
apex examples : http://apex.oracle.com/pls/otn/f?p=11933:5