I have a problem getting my subreport to work properly when used in an xaction created in design studio. Description of the problem with an example follows:

The xaction is designed as follows:
Step 1. The user selects different input-parameters for the report especially different targetids.
Step 2. SQL-Query is generated with the inputs to retrieve the data for the main part of the report.

Problem:
Step 3. The output is grouped by the targetid. For every group I want to display a subreport with a chart depending on these input-parameter.
What do I have to enter in the "Subreport Data/Queries" of the "Pentaho Report" step so that for each group one chart is displayed? Currenty I get "No data available ...".

In the report generated in report designer my query looks like this:
Code:
SELECT 
airline,
airlineid,
flightprice,
flightdate,
targetname,
targetid,
CONCAT(airline, "_", DATE_FORMAT( flightdate, '%d.%m.%Y' )) as chartgroup

FROM flights

WHERE flightdate >= "2009-10-11 00:00:00" 
    AND flightdate < "2009-10-18 00:00:00" 
    AND airlineid IN ('1067','1071','1072') 
    AND targetid IN ( ${targetid} ) 
GROUP BY chartGroup
ORDER BY flightdate, airline ASC
So for each targetid the data will be retrieved and a chart can be printed.

Example (how the report should look like):

Target: Airport1
Airline Day1 Day2 Day3
Airline1 $200 $240 $270
Airline2 $310 $315 $280
...

Chart displaying the days on the x-axis and the prices on the y-axis.

Target: Airport2
Airline Day1 Day2 Day3
Airline1 $220 $140 $370
Airline3 $210 $115 $380
...

Chart displaying the days on the x-axis and the prices on the y-axis.