jasper report subreport help

[samuele.vigano]

hello i'm using this xpath to create a report in Jaspersoft studio :

 

this is my structure:

<olympicBeanSet>

<olympicBean id='posShares'>

<occurrence index = '1'>

<property name  ='Description'>

<value>CIR AOIR </value>

</property>

<property name ='PPT_MONEVA'>

<value> EUR

</value>

</property>

</occurrence>

<occurrence index ='2'>

<property name  ='Description'>

<value>BANK </value>

</property>

<property name ='PPT_MONEVA'>

<value> USD

</value>

</property>

</occurrence>

so, for the first: i'm trying to create a report with a lot of different informations from this xml file. a specific part of my report needs all occurrence from posShares node, i try to explain: for example you have to suppose that i have 30 occurrence and i want to print for each of them , their property = description and property = PPT_MONEVA. unfortunatelly i haven't a database but only an xml file, so i don't know exactly how to obtain this. i tried to add a subreport with a specific path from my xml file but when i return the value in a variable i obtain only : NULL so i tried to insert a parameter from master report to sub report to " print when expression " and i tried to evaluate the value of my input parameter but again i obtain :NULL please anyone can help me?