Действие при выборе выпадающего списка

<?php  
session_start();  
 
$year = array('Москва','Воронеж','Пермь'); 
 
if (isset($_POST['year'])) 
{ 
$key = array_search($_POST['year'], $year); 
     
if ($key!==false) { $_SESSION['year'] = $year[$key]; }     
} 
  
 
?>  
<br><strong>Select town:</strong><br><br>  
<form action="#" onChange="this.form.submit()">  
<select name="year">   
 
<?php foreach ($year as $value): ?> 
<option value="<?php echo $value; ?>"  
<?php if ($_SESSION['year'] == $value) {echo "selected";}?>> <?php echo $value; ?> </option>  
<?php endforeach; ?> 
</select>  
</form>  
<br>  
<a href="./page.php">Page</a>

form action='#'  onchange='this.form.submin()' name='f'>  
<select name='year'>   
<option value='1'>Москва</option>
<option value='2'>Рязань</option>
</select>
</form>
<?php  var_dump($_POST); ?>

<form action="#" method="POST">
    <select id="test" name="test" onchange="this.form.submit();">
        <option value="1">1</option>
        <option value="2">2</option>
        <option value="3">3</option>
        <option value="4">4</option>
        <option value="5">5</option>
    </select>
</form>
<?php  var_dump($_POST); ?>