Doubt/Clarification plz

[rbojja]

Hi

When i am trying to generate a master/sub report, iam passing subreport expression as $P{SubreportParameter}

and declaring this variable in master report.

 

But this is not showing up the subreport values on the main report.

 

But when i am using the subrpeort expression as ".jasper" then it is showing the subrpeort values on

main report.

 

whats the difference.Some ppl say use $P{SubreportParameter} and some say use ".jasper"

 

Can any one clarify my doubt.