How do I render a grid only on the last page in BIRT?

How do I render a grid only on the last page in BIRT?

Using BIRT 3.7.2, I'm trying to place a grid at the bottom part of the
last page of a report for signatories. However I can't seem to find a way
to do that.
I've tried to place the grid in a footer and render it using:
if(BirtComp.lessThan(pageNumber, totalPage)) {
this.getStyle().display = "none";
}
on the grid's onRender. However this only works on the webviewer, and I
need it to work in PDF with my Java application. When I use run and
format=pdf parameters, there is still that grid at every page, and using
frameset instead of run makes it not appear at all. Are there other
techniques to do this? If else I may have to settle for placing the
signatory grid below the table data so at least it will be on the last
page.