Dynamically Update a number field by summing of page item values.

Question

Hi,
I'm trying to update a number field on an apex page by summing up the values of multiple page items. I've tried to follow this tutorial http://st-curriculum.oracle.com/obe/db/apex/r40/apexdynactions/apexdynactions_ll.htm , especially the "Create a Set Value Dynamic Action Using PL/SQL" part.
In the tutorial example they return an page item value P3_SAL multiplied by a multiplier they've determined by another page item's case. What I want to do is much simpler in that I just want to add up multiple page item values and then display them in a number field at the bottom of the page.
so the code I tried to use based on the tutorial is in the tab: Home >Application Builder>Application 103>Page 3>Edit Dynamic Action>Create / Edit Action
Set Type: PL/SQL Function Body
PL/SQL Function Body:
BEGIN
return :P3_ITEM1+P3_ITEM2+P3_ITEM3;
END;
Page Items to Submit: P3_ITEM1,P3_ITEM2,P3_ITEM3
But it gives me an error that I need to declare the identifiers, yet it works if I only use one item and I can perform any arithmetic.
ie.
BEGIN
return :P3_ITEM1+1000;
END;
Any help would be appreciated.

Answer 1

PL/SQL Function Body:
BEGIN
return :P3_ITEM1+P3_ITEM2+P3_ITEM3;
END;
Page Items to Submit: P3_ITEM1,P3_ITEM2,P3_ITEM3
But it gives me an error that I need to declare the identifiers, yet it works if I only use one item and I can perform any arithmetic.In your code is missing the ":" for the items P3_ITEM2 and P3_ITEM3.
Try this:
BEGIN
return :P3_ITEM1+:P3_ITEM2+:P3_ITEM3;
END;