Form submission handler for system_settings_form().
If you want node type configure style handling of your checkboxes, add an array_filter value to your form.
function system_settings_form_submit($form, &$form_state) {
// Exclude unnecessary elements.
form_state_values_clean($form_state);
foreach ($form_state['values'] as $key => $value) {
if (is_array($value) && isset($form_state['values']['array_filter'])) {
$value = array_keys(array_filter($value));
}
variable_set($key, $value);
}
drupal_set_message(t('The configuration options have been saved.'));
}