Wordpress Pagination with Custom Query - pagination

Question

I am attempting to write a plugin that searches an SQL table based on input supplied via a form. My code is...
global $table_name_log;
$pagenum = isset( $_GET['pagenum'] ) ? absint( $_GET['pagenum'] ) : 1;
$limit = 25;
$offset = ( $pagenum - 1 ) * $limit;
$l_task=isset( $_POST['l_task'] ) ? $_POST['l_task'] : "a";
$l_val=$_POST['l_val']; if($l_val=="") { $l_task="a"; }
if($l_task=="d")
{
$criteria="where log.Doc_Number='{$l_val}'";
}
elseif($l_task=="e")
{
$criteria="where log.Employee='{$l_val}'";
}
else
{
$criteria="";
}
$SQLQuery="SELECT em.ID, log.Date, em.Payroll, log.Doc_Number, doc.Doc_Name, doc.Replaced_By, log.Trainer, log.Log, log.Type
FROM {$table_name_log} log
join {$table_name_employee} em on log.Employee=em.ID
join {$table_name_documents} doc on log.Doc_Number=doc.Doc_Number
{$criteria}
order by log.Employee asc
";
//Get total number of results
$results=$wpdb->get_results("{$SQLQuery}",ARRAY_A);
$search_total = $wpdb->num_rows;
//Limit results by page
$results=$wpdb->get_results("{$SQLQuery} LIMIT {$offset}, {$limit}",ARRAY_A);
if(! $results)
{
if($pagenum>1)
{
$pagenum=1;
$results=$wpdb->get_results("{$SQLQuery} LIMIT 0, {$limit}",ARRAY_A);
}
}
I then display the results of the query.
At the bottom of the displayed results I have this code...
$total=$search_total;
$num_of_pages = ceil( $total / $limit );
$page_links = paginate_links( array(
'base' => add_query_arg( 'pagenum', '%#%' ),
'format' => '',
'prev_text' => __( '«', 'aag' ),
'next_text' => __( '»', 'aag' ),
'total' => $num_of_pages,
'current' => $pagenum
) );
if ( $page_links ) {
echo '<div class="tablenav"><div class="tablenav-pages" style="margin: 1em 0">' . $page_links . '</div></div>';
}
The problem is that although the number of pages is calculated correctly and page 1 displays the correct results; when selecting another page it displays the results without the $criteria set by $l_task. How do I edit the code so that the pagination links feed the correct query to use for the additional pages?

Answer 1

Works now by adding this at the top...
if(isset($_GET['l_task'])) { $_POST['l_task']=$_GET['l_task']; }
if(isset($_GET['l_val'])) { $_POST['l_val']=$_GET['l_val']; }
I then added this...
'add_args' => array( 'l_task' => $_POST['l_task'], 'l_val' => $_POST['l_val'] )
to...
$page_links = paginate_links( array(
'base' => add_query_arg( 'pagenum', '%#%' ),
'format' => '',
'prev_text' => __( '«', 'aag' ),
'next_text' => __( '»', 'aag' ),
'total' => $num_of_pages,
'current' => $pagenum,
'add_args' => array( 'l_task' => $_POST['l_task'], 'l_val' => $_POST['l_val'] )
) );