Is there a module to conditionally set a fields value depending another field?
No other module available apart from conditional field, you need to create your own module with hook form_alter() and use some code like

&lt;?php
function wishlist_status_form($form_state) {
$form['status'] = array(
    '#type' =&gt; 'textfield',
    '#title' =&gt; 'Status',
    '#suffix' =&gt; '&lt;div id="my-wrapper"&gt;&lt;/div&gt;',
  );

$form['ajax-submit'] = array(
    '#type' =&gt; 'submit',
    '#ajax' =&gt; array(
        'callback' =&gt; 'wishlist_status_change',
        'wrapper' =&gt; 'my-wrapper',
    ),
    '#value' =&gt; t('Save'),
  );
return $form;
}

function wishlist_status_change($form, $form_state) {
    dpm($form_state, 'state callback');
    return 'test';
}
?&gt;