1 charts, 3 series, 1 query by series. Dataset ?

Hi,

I begin with JasperSoft, and I'm trying to create a chart with multiples query.

My point is to have 1 chart with 3 series, and 1 different query by serie.

I've try to use dataset, but I can only have ONE datasource for my chart, and I don't understand how to use my 3 dataset in my chart.

Could you explain me if it's possible, and how to do in this case ?

Thanks a lot for your help.