guarda se va bene :master:
codice:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title>Pagina senza titolo</title>

    <script language="javascript" type="text/javascript">
// <!CDATA[
function visualizza(v)
{
    var ds = v.parentNode.getElementsByTagName("div");
    if(!ds || ds.length == 0) return;
    var d = ds[0];
    d.style.display = (d.style.display == "")? "none": "";
}

// ]]>
    </script>

</head>
<body>
    <div>
        Contenuto1
        <div style="display:none;">testo1</div>
    </div>
    <div>
        Contenuto2
        <div style="display:none;">testo2</div>
    </div>
    <div>
        Contenuto3
        <div style="display:none;">testo3</div>
    </div>
    <div>
        Contenuto4
        <div style="display:none;">testo4</div>
    </div>
    
</body>
</html>