php - FPDF A4 Paper not print last row -

i'm trying make printing rows on a4 paper, no matter number of rows. it's important rows occupy entire length of a4 paper (297mm).

example:
so, if want 4 rows means entire length of paper a4 divided 4 , print 4 rows equally occupy entire a4 paper. problem last row printed on different paper.
don't know why?
have advice how solve problem?

here php code:

<?php   require('fpdf/fpdf.php');  class pdf extends fpdf { }  $pdf = new pdf('p', 'mm', array(210, 297));  $pdf->setfont('arial', '', 8); $pdf->addpage(); $widhtmm = 210;  $pdf->setmargins(0, 0, 0, 0); $heightmm = 295;  $pdf->setxy(0, 0); $margintop = 0;  $rows = 7; $testo = '';  for($i = 0; $i < $rows; $i++) {      $heightmm = 297 / $rows;      if ($i == 0) {         $margintop = 0;     } else {         $margintop += $heightmm;     }      $pdf->setxy(0, $margintop);     $pdf->cell($widhtmm, $heightmm, $heightmm, 'lrtb', 0, 'l', 0);     $pdf->ln();  } $pdf->output();  ?> 

you need set auto page break before add page (by default 2cm bottom margin):

$pdf->setautopagebreak(true, 0); 

http://www.fpdf.org/en/doc/setautopagebreak.htm

and better if change code little bit:

$heightmm = 297 / $rows;  for($i = 0; $i < $rows; $i++) {      $margintop = $i*$heightmm;      $pdf->setxy(0, $margintop);     $pdf->cell($widhtmm, $heightmm, $heightmm, 'lrtb', 0, 'l', 0);     $pdf->ln();  }