$modsince = preg_replace( '/;.*$/', '', $_SERVER['HTTP_IF_MODIFIED_SINCE'] );
$sinceTime = strtotime( $modsince );
if ( $stat['mtime'] <= $sinceTime ) {
$modsince = preg_replace( '/;.*$/', '', $_SERVER['HTTP_IF_MODIFIED_SINCE'] );
$sinceTime = strtotime( $modsince );
if ( $stat['mtime'] <= $sinceTime ) {