Unnamed

<select name="sector">
  <option value="z" selected="selected">&nbsp;</option>
  <option value="norte">Norte <? $sector = 0; ?> </option>
  <option value="oriente">Oriente <? $sector = 1; ?> </option>
  <option value="centro">Centro <? $sector = 2; ?> </option>
  <option value="poniente">Poniente <? $sector = 3; ?> </option>
  <option value="sur">Sur <? $sector = 4; ?> </option>
</select>

<select name="establecimiento">
  <option selected="selected">&nbsp;</option>
  <?
	switch($sector){
	case 0:	echo "<option>Colegio Andres Bello</option>";	
		echo "<option>Colegio Lucila Godoy</option>";
		echo "<option>Escuela España</option>";
		break;
	case 1:	echo "<option>Colegio Ingles</option>";
		echo "<option>Escuela Pablo Neruda</option>";
		echo "<option>Escuela Pretoriana</option>";
		break;
	case 2:	echo "<option>Colegio De La Salle</option>";
		echo "<option>Colegio Integrado</option>";
		echo "<option>Escuela Basica</option>";
		echo "<option>Escuela San Agustin</option>";
		break;
	case 3:	echo "<option>Colegio Concepcion</option>";
	        echo "<option>Colegio Montessori</option>";
		break;
	case 4: echo "<option>Colegio San Andres</option>";
		echo "<option>Escuela Padre Hurtado</option>";
		echo "<option>Escuela Tito Fernandez</option>";
		break;
	}
  ?>                  
</select>