codice:
<script type="text/javascript" src="http://code.jquery.com/jquery-latest.pack.js"></script> 
<script>
 $(document).ready(function(){  alert(document.test.id_pacchetto[0].value);   });   </script> </head>
  <body>
 <form name="test">
 <input name="id_pacchetto" type="checkbox" value="1"> 1 <input name="id_pacchetto" type="checkbox" value="2"> 2 <input name="id_pacchetto" type="checkbox" value="3"> 3 <input name="id_pacchetto" type="checkbox" value="4"> 4 </form>  </body> </html>
è un array il checkbox