Soumettre le formulaire sur le changement
<form action="myservlet.do" method="POST">
<select name="myselect" id="myselect" onchange="this.form.submit()">
<option value="1">One</option>
<option value="2">Two</option>
<option value="3">Three</option>
<option value="4">Four</option>
</select>
</form>
4MBL