test multiple select
limiter le nb de slection a 2 et forcer l'affichage
HTML
<select name="selector" id="selector" multiple="multiple" data-overlay-theme="c" data-theme="c" data-icon="grid" data-iconpos="left" data-native-menu="true">
<optgroup label="Animaux">
<option value="cheval" selected="selected">cheval</option>
<option value="mouton">mouton</option>
<option value="boeuf">boeuf</option>
<option value="etc">etc</option>
</optgroup>
<optgroup label="Objet">
<option value="Table">Table</option>
<option value="lampe">lampe</option>
<option value="etc">etc</option>
</optgroup>
</select>