Display checkboxes as a dropdownlist?

Display checkboxes as a dropdownlist?

Hi, 

I have some checkboxes that I need to display them in a drop down list. I was searching on internet but I didn't find the solution for my case. Here is the code:

<div class="amenities">
<ul>
<li class="junio">
<input id="amenity553a208be5c793" type="checkbox" value="5" name="filter_amenities[]">
<label for="amenity553a208be5c793">Junio</label>
</li>
<li class="julio">
<input id="amenity653a208be5c793" type="checkbox" value="6" name="filter_amenities[]">
<label for="amenity653a208be5c793">Julio</label>
</li>
<li class="agosto">
<input id="amenity753a208be5c793" type="checkbox" value="7" name="filter_amenities[]">
<label for="amenity753a208be5c793">Agosto</label>
</li>
<li class="setiembre">
<input id="amenity853a208be5c793" type="checkbox" value="8" name="filter_amenities[]">
<label for="amenity853a208be5c793">Setiembre</label>
</li>
</ul>
<input type="hidden" value="0" name="filter_amenities[]">
</div>

if somebody can help me please, 

Anna.