I am creating some theme settings and am creating a form to populate them in
theme-settings.php. I am using the hook
I would like to restrict or verify that only numbers can be entered into a field. I've searched online but have not found how to do this. Would anyone know what I ought to add to my code?
Code currently looks like:
$form['mysite_theme']['mysite_contact_phone'] = array( '#type' => 'textfield', '#title' => t('Contact Number'), '#default_value' => $default['mysite_contact_phone'], '#description' => t('Enter the main contact number for this site.'), '#required' => TRUE, );