Wybrana opcja JQuery
$( "#myselect option:selected" ).val();
Difficult Duck
$( "#myselect option:selected" ).val();<select id="menu">
<option value="1">Opción 1</option>
<option value="2">Opción 2</option>
<option value="3">Opción 3</option>
</select>
<script >
$(function () {
$("#menu option[value='2']").attr("selected", true);
});
</script>$('select option[value=8272]').attr('selected', '');