Can you set the value of a hidden variable when submitting a form?

[DeX]

Here's my PHP form code:

 

					<form method='POST' action="<?php basename($_SERVER['PHP_SELF']);?>" onSubmit="return stripInputBoxes(1)">
					<?php
						echo "<div id = 'purchaseOrderRow1' style = 'display:none;border: 1px solid black;'>";
						echo $integrityBuildingProductsPDF;
						echo '<input type = "hidden" id = "pdf1" value = "" name = "pdf1" />';
						echo '<button name = "savePurchaseOrder" type = "submit">Save Purchase Order</button>';
						echo "</div>";
					?>


				</form>

 

Here's my Javascript:

function stripInputBoxes(pdfNumber)
{
if (!document.getElementsByTagName) return;

for (i = 0; i < document.getElementById('tableBody').getElementsByTagName('tr').length - 3; i++)
{
	document.getElementById(i).parentNode.innerHTML = document.getElementById(i).value;
}

document.getElementById("pdf" + pdfNumber).value = "ljkasdkljf";

	return true;
}

 

Will this set the value of the hidden variable? I'm trying to echo the value of $_POST['pdf1'] but it comes out to nothing when the page reloads. How do I do this?

What I'm trying to do here is display a purchase order on the screen and the user can edit the quantities in the purchase order. They click SAVE to save the new updated quantities and it auto generates a PDF that's saved on the server with those new quantities. The problem is I need to run the stripInputBoxes function to take the <input> tags out of the HTML code before creating the PDF because the PDF generator doesn't recognize the tags.