meerdere documenten tegelijk afdrukken

<?php 
$path = '/pad/naar/de/pdfs/'; 
$files = glob( $path . '*.pdf' ); 
if( is_array( $files ) && count( $files ) > 0 ) { 
    sort( $files ); 
    foreach( $files AS $file ) { 
	echo "<input type=\"checkbox\" name=\"checkbox\" id=\"checkbox\" onClick=\"javascript:window.print()\">";
        printf( '<a href="/mappen/van/pdfs/%1$s" target="_blank">%1$s</a><br />', 
            basename( $file ) 
        );
    } 
} 
else { 
    echo 'Er zijn geen PDF bestanden in de map' . $path; 
} 
?>

<?php 
$path = '/pad/naar/de/pdfs/'; 
$files = glob( $path . '*.pdf' ); 
if( is_array( $files ) && count( $files ) > 0 ) { 
    sort( $files ); 
    foreach( $files AS $file ) { 
	echo "<input type=\"checkbox\" name=\"checkbox\" id=\"checkbox\" onClick=\"javascript:window.print()\">";
        printf( '<a href="/mappen/van/pdfs/%1$s" target="_blank">%1$s</a><br />', 
            basename( $file ) 
        );
    } 
} 
else { 
    echo 'Er zijn geen PDF bestanden in de map' . $path; 
} 
?>

<?php
if(isset($_POST['submit']))
{
	foreach($_POST['checkbox'] as $checked => $value)
	{
		// print actie
	}
}
else
{
	echo
	'<form method="post" action="">
		<input type="checkbox" name="checkbox[]" value="pdf0.pdf" />pdf0<br />
		<input type="checkbox" name="checkbox[]" value="pdf1.pdf" />pdf1<br />
		<input type="submit" name="submit" value="Verstuur" />
	</form>';
}
?> 

<?php
if(isset($_POST['submit']))
{
	foreach($_POST['checkbox'] as $checked => $value)
	{
		// print actie
	}
}
else
{
	echo
	'<form method="post" action="">
		<input type="checkbox" name="checkbox[]" value="pdf0.pdf" />pdf0<br />
		<input type="checkbox" name="checkbox[]" value="pdf1.pdf" />pdf1<br />
		<input type="submit" name="submit" value="Verstuur" />
	</form>';
}
?>