Anonymous

if (isset($a)) {
 if ($a == blabla) { include('page1.php'); }
 elseif ($a == blabla2) { include('page2.php'); }
 //ir taip toliau:)
}
//jeigu nori dar galima includint kita psl jeigu $a neuzsetintas:
else { include('kitas.php'); }