I wanted to destroy the session because I want a new session to start with new values for each variable, every time a new search is made. But it still doesn't work. I changed it to this...
session_start();
header("Cache-control: private"); //IE 6 Fix
if ($start_new_search == "1") {
session_destroy();
$_SESSION['term1'] = '';
$_SESSION['term2'] = '';
}
$_SESSION['term1'] = $term1;
$_SESSION['term2'] = $term2;
$SID=session_id();