JSFiddle - React, Tailwind, and code Playground
HTML
<script src="http://www.francescomigliorato.it/restyling/js/jquery.chained.js"></script>
<link rel="stylesheet" href="http://www.francescomigliorato.it/restyling/chosen/chosen.css">
<script src="http://www.francescomigliorato.it/restyling/chosen/chosen.jquery.min.js"></script>
<li>
<label for="progetto">Progetto</label>
<select name="progetto" id="progetto" data-placeholder="Tipo di progetto" style="width:210px;" class="chzn-select" tabindex="4">
<option value="">Scegli...</option>
<option value="sito">Sito Web</option>
<option value="fotoritocco">Fotoritocco</option>
<option value="fotodvd">Foto DVD</option>
<option value="altro">Altro</option>
</select>
</li>
<li>
<label for="budget">Budget</label>
<select name="budget" id="budget" data-placeholder="Budget" style="width:210px;"" class="chzn-select" tabindex="5"">
<option value="">--</option>
<option value="1000" class="sito">€ 1000</option>
<option value="2000" class="sito">€ 2000</option>
<option value="3000" class="sito">€ 3000</option>
<option value="50" class="fotoritocco">€ 50,00</option>
<option value="100" class="fotoritocco">€ 100,00</option>
<option value="200" class="fotoritocco">€ 200,00</option>
</select>
</li>
<script type="text/javascript">
$(".chzn-select").chosen({disable_search_threshold: 10});
$(".chzn-select-deselect").chosen({allow_single_deselect:true});
</script>
<script type="text/javascript" charset="utf-8">
$(function() {
$("#budget").chained("#progetto"); /* or $("#series").chainedTo("#mark"); */
});
</script>