codice:
<?xml version="1.0" encoding="iso-8859-1"?>

  <!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" xml:lang="en" lang="en">
    <head>
      <title>Code Example by DYNAMIC+</title>

      <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
      <meta http-equiv="Content-Language" content="en-us" />

      <script type="text/javascript">
      <!--

        function checkData( __objForm )
        {
          var _errDescription = "";
          var _errLastInvalid = null;

          if ( !__objForm.elements['Title'].value.length )
          {
            _errLastInvalid = __objForm.elements['Title'];
            _errDescription += "  - il titolo è mancante\n";
          }

          if ( !__objForm.elements['Message'].value.length )
          {
            _errLastInvalid = __objForm.elements['Message'];
            _errDescription += "  - il messaggio è vuoto\n";
          }

          if ( !__objForm.elements['Categoria'][0].checked &&
               !__objForm.elements['Categoria'][1].checked &&
               !__objForm.elements['Categoria'][2].checked )
          {
            _errLastInvalid = __objForm.elements['Categoria'][0];
            _errDescription += "  - nessuna categoria selezionata\n";
          }

          if ( _errLastInvalid == null )
            return true;

          else {
            alert( "Si sono verificati i seguenti errori:\n" + _errDescription + "\n" +
                   "Correggerli e riprovare l'invio del form!" );

            _errLastInvalid.focus( );
            return false;
          }
        }

      //-->
      </script>

    </head>
    <body>

      <div>
        <form method="post" enctype="multipart/form-data"" action="oknuova.asp?Det=<%=Det%>" onsubmit="return checkData( this );">

          <input type="text" name="Title" size="40" />

 
          <table width="100%" border="0" cellspacing="1" cellpadding="2">
            <tr bgcolor="#BBBBFF"> 
              <td><input type="radio" name="Categoria" value="2" /></td>
              <td>Information on-line</td> 
            </tr>

            <tr bgcolor="#BBBBFF"> 
              <td><input type="radio" name="Categoria" value="3" /></td> 
              <td>Lettere aggiornamenti</td> 
            </tr>

            <tr bgcolor="#BBBBFF"> 
              <td><input type="radio" name="Categoria" value="4" /></td> 
              <td>Note</td> 
            </tr> 
          </table>

          <textarea name="Message" rows="6" cols="70"></textarea>
 
          <input type="submit" value=" Aggiungi " name="SUBMIT2">
 

        </form>
      </div>

    </body>
  </html>