MultAxis Bar Graph Problem

[bandellwork]

I am working on a school project and need a little help. A little background of what I am trying to do. I have a query that brings back sales totals for each month of a year for products, services, and maintance. so the results look like the following.

Month   Sales ProdOrSales

Jan        10000   Services

Jan         2500     Products

Jan        1000     Maintance

Feb        9000     Services

Feb         3000      Products

Feb         1500     Maintance

and so on for each month

I am trying to create a multi axis chart that includes a line graph and a bar graph. The line graph works the way I want it to. Each category has it's own line (Services, Products, Maintance). I am having problems with the bar graph. I want the bar graph to total all three categories for each month. However it only goes up to the category that has the highest amount. Any ideas on how I can sum the totals for the month.    Thanks for any help.

[bandellwork]

Update. I used the sum Sales_Sum automatically generate by iReports. The problem now is that it keeps a running sum from month to month. So Jan the bar would be 13500 Feb 27000 and so on. Is there a way to reset sum to 0 for each month?