Label change in Credit Note Report

Hello,

I need to change label from Total Charges to Freight Charges in Sales Invoice report and in Credit Note report.  I made changes in SalesInvoiceReport from Visual Studio 2012 (opened Application Explorer -> Visual Studio Projects -> Dynamics AX Model Projects and then opened SalesInvoiceReport).  I have changed the label in the expression.

I am able to see the label change in Sales Invoice but unable to see the change in Credit Note, could any one tell me what needs to be done.

I learned that the same report is used for both SalesInvoice and credit note is this true? if so why I am unable to see the label change for credit note.

Thanks in advance!!