Creating charts in RS

I'm new to reporting services and while on the whole it is simple enough, I am running into some problems trying to create a chart for a monthly sales comparison report.

Each monthly summary chart has four charted fields, Finance, Lease, Cash, and Outside. I had no trouble at all creating a chart to display those four values, however when I try to create a report comparing the last three months I am not able to get the data grouped correctly.

In the report for a single month, the data fields simply get dropped in the data fields area of the report layout screen. In the case of the comparison report there are twelve fields instead of four, if I put them all in the data fields area they simply appear as one group on the chart. What I need to do is group the three Finance fields together, Lease fields together, Cash fields together, and Outside fields together while setting the series colors to be the same for each set of monthly data. So that this months Finance, Lease, Cash, and Outside fields all display in the same color, last months fields are the same color, ect.

I have spent several hours playing with the group and series properties of the chart and searching the net for help with this and have not found a solution. ANY help with this would be much appreciated.

Thanks,

Joe