dynamic form dropdown

[eluser]jonyork[/eluser]
I managed to simplify things, but im still not getting it to work properly

Code:

<?php
    
    $salutation = array(
        'Mr.' => 'Mr.',
        'Mrs.' => 'Mrs.',
        'Dr.' => 'Dr.',
        );    
    
    echo form_open('membership/update');

    echo form_dropdown('Salutation', $salutation, 'Mrs.');

?>

The dropdown is posting the value to the database, so that is good, however, the third option 'Mrs.' is not selected by default.

How can I get that to work?