Queries :: Calculation Query To Add Values Of Three Fields

I created a simple calculation query to add the values of three fields:

Program_Cost, Auditorium_Cost and Millage_Fee.

I followed the steps found here: [URL] ....

But it doesn't work. The query pulls the values for the relevant fields but doesn't actually calculate the total. What am I doing wrong? Here's the query's SQL:

SELECT [Event Information].Event_ID, Sum([Program_Cost]+[Millage_Fee]+[Auditorium_Cost]) AS Total_Cost, [Event Information].Program_Cost, [Event Information].Auditorium_Cost, [Event Information].Millage_Fee
FROM [Event Information]
GROUP BY [Event Information].Event_ID, [Event Information].Program_Cost, [Event Information].Auditorium_Cost, [Event Information].Millage_Fee;