celkom sikovny snippet ako zmenit hodnoty selektu potom ako sa ulozia uz nejake nody

// Get the field info
$info = field_info_field('field_some_field');

// Get a reference to the values
$values = &$info['settings']['allowed_values'];

// Manipulate the values in some way, e.g.
$values['new_value'] = 'New Value';

// Save the field
field_update_field($info);