[jQuery] Hide function problem in IE8

[ciupaz]

Hi all,
I have this jQuery snippet to hide a "DIV" block when the user select
one value of a radio button:

<script type="text/javascript">
                        $(document).ready(function() {
                                $("input[name='persona']").change(function() {
                                        if 
($("input[name='persona']:checked").val() == '0') {
                                                alert('PersonaFisica');
                                                $('#ragioneSocialeLine').hide();
                                                $('#partitaIvaLine').hide();
                                                $('#sedeLegale').hide();
                                                $('#nomeCognomeLines').show();
                                                $('#generalitaLines').show();
                                        }
                                        else {
                                                alert('PersonaGiuridica');
                                                $('#ragioneSocialeLine').show();
                                                $('#partitaIvaLine').show();
                                                $('#sedeLegale').show();
                                                $('#nomeCognomeLines').hide();
                                                $('#generalitaLines').hide();
                                        }
                                });

                                $("input[name='persona']").trigger('change');


and

<span class="sportelloamiacque_formfield">
                                                                <input 
type="radio" id="personaFisica" name="persona"
value="0" /> Persona fisica
                                                                <input 
type="radio" id="personaGiuridica" name="persona"
value="1" /> Persona giuridica
                                                        </span>

The problem is that the user "must"click 2 times to obtain that
functionality in IE8, and it works correctly in Firefox and Chrome.

How can I solve this strange problem?

Thanks a lot.

Luigi