Send variable from form submit into fpdf

i have a form…

<form method=“post” action=“tambah_vendor.php”>
<input name=“id_produk” type=“text” size=“20” />
<input type=“submit” name=“input_produk” value=“Insert” />

i want to send to this fpdf page…
$pdf=new FPDF(‘P’,‘mm’,‘Legal’);
$pdf->SetFont(‘Times New Roman’,‘B’,12);

it’s not errors but variable $id_produk doesn’t want to show, can anybody help me?

Try pass $id_produk to function, without quotes.

$pdf->MultiCell(0,10, $id_produk, 0,'J');