Different page margin with a text field containing dynamic data with stretch overflow

[giovannadile]

I'm using IReport 5.6.0 and I have a report contains dynamic data of multiple pages. I have to respect a line spacing size of 28.35, so I have a fixed number of lines in each page (25), but I dont'know in advance the length of text field in each page, so I cant'separe the text field for each page. I create a text field that stretchs overflow in more pages but I want to set different page margin for front and back page. I duplicate the text field and set a variable value in Print when expression depending on the odd vs even pages, but my problem is that the page number doesnt'work in the print expression because the text field stretchs overflow in the detail band or in group header/footer. The variable page_number works only on the first page. How can I resolve this topic?

Thank you!