"Cummilative Sum"

I've got a view with the following data: (Sample)

Class Date Month Year Day Target Actual Variance MName
====================================================================
DropBalling 01/07/2005 7 2005 1 165000 117850 -47150 July
DropBalling 02/07/2005 7 2005 2 165000 92550 -72450 July
DropBalling 03/07/2005 7 2005 3 165000 171900 6900 July
DropBalling 04/07/2005 7 2005 4 165000 66850 -98150 July
Lancing 01/07/2005 7 2005 1 90000 44100 -45900 July
Lancing 02/07/2005 7 2005 2 90000 129650 39650 July
Lancing 03/07/2005 7 2005 3 90000 85450 -4550 July
Lancing 04/07/2005 7 2005 90000
Plant 01/07/2005 7 2005 67000
Plant 02/07/2005 7 2005 2 67000 18150 -48850 July
Plant 03/07/2005 7 2005 3 67000 6150 -60850 July
Plant 04/07/2005 7 2005 67000

I want to create a chart, which looks like this:http://www.tjoppie.co.za/chart.jpg .. So what I'll have to do is "cummilate sum" everyday's targets and actuals. How can I do this?

Thanks
Rudi

[1127 byte] By [Tjoppie] at [2008-2-10]