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 di prova</title>
    <link rel="stylesheet" href="css/style.css" type="text/css" media="screen"/>
    <script language="javascript" type="text/javascript">
// <!CDATA[
function visualizza(v)
{
    var strillo = document.getElementById("strillo");
    if(strillo.style.display == "none") strillo.style.display = "block";
    strillo.innerHTML = "Informazioni per "+v.text;
}

// ]]>
    </script>

</head>
<body>
    <div>
        Titolo1
    </div>    
    <div>
        Titolo2
    </div>
    <div>
        Titolo3
    </div>
    <div>    
        Titolo4
    </div>
    
  <div id="strillo" style="display:none;"></div>

</body>
</html>