Footer should be print on last page using smartforms

Hi Experts,

I have to print footer on last page in smartforms.

for ex-if pages printing from 1-10 then footer should be displayed on 10th page but the size of main window should be expand up to end of the pages 1-9 .that means if hight of the main window is 15 cm and hight of footer 3 cm then main window should be expand 15+3 = 18 for 1-9 page and on last page hight of the main window should be 15 and remaining 3 for footer.

how to built logic.

plz reply.