<form action="./php/form.php" method="POST" />
<button type="submit" value="action" name="nazwa" value="1">1</button>
<button type="submit" value="action" name="nazwa" value="2">2</button>
</form>

PHP:
<?php
switch ($_POST['nazwa']) {
    case 1:
    break;
    case 2:
    break;
}