there is only one for element, this is pretty easy.
add the following a line 1 of your results page:
<?php
@session_start();
if(isset($_GET['knowledgebase'])) {
$_SESSION['knowledgebase'] = $_GET['knowledgebase'];
}
?>
then add this code after the body to display the search term:
<?php echo(isset($_SESSION['knowledgebase'])?$_SESSION['knowledgebase']:""); ?>