Wrapp every form item select with div, excluding label im trying  to wrap form item  with 

I had success with hook_from_alter and #prefix #suffix that is wrapping whole element with div like this:

I used this hook:

function em_form_alter(&amp;$form, &amp;$form_state, $form_id){
if ($form_id == 'user_register_form') {
    $form['field_gender'][LANGUAGE_NONE]['#prefix'] = '&lt;div class="custom-select"&gt;';
    $form['field_gender'][LANGUAGE_NONE]['#sufix'] = '&lt;/div"&gt;';
}
}


And i got this.

&lt;div class="custom-select"&gt;
&lt;div class="form-item form-type-select form-item-field-gender-und"&gt;
    &lt;label for="edit-field-gender-und"&gt;Gender&lt;/label&gt;
    &lt;select id="edit-field-gender-und" name="field_gender[und]" class="form-select required"&gt;
        &lt;option value="_none"&gt;- Select a value -&lt;/option&gt;
        &lt;option value="1"&gt;Male&lt;/option&gt;
        &lt;option value="2"&gt;Female&lt;/option&gt;
    &lt;/select&gt;
&lt;/div&gt;




But what i need to accomplish is this:

&lt;div class="form-item form-type-select form-item-field-gender-und"&gt;
&lt;label for="edit-field-gender-und"&gt;Gender&lt;/label&gt;
&lt;div class="custom-select"&gt;
    &lt;select id="edit-field-gender-und" name="field_gender[und]" class="form-select required"&gt;
        &lt;option value="_none"&gt;- Select a value -&lt;/option&gt;
        &lt;option value="1"&gt;Male&lt;/option&gt;
        &lt;option value="2"&gt;Female&lt;/option&gt;
    &lt;/select&gt;
&lt;/div&gt;




And i would like to have this on every select on whole website, so maybe hook_form_alter isn`t so good idea?
This theme function should do what you need.

function mytheme_select($variables) {
  $element = $variables['element'];
  element_set_attributes($element, array('id', 'name', 'size'));
  _form_set_class($element, array('form-select'));

  return '&lt;div class="custom-select"&gt;&lt;select' . drupal_attributes($element['#attributes']) . '&gt;' . form_select_options($element) . '&lt;/select&gt;&lt;/div&gt;';
}