Cosi

codice:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>
<head>
<title>Untitled</title>
<script language="JavaScript" type="text/javascript">
<!--
function show(aDivName,showStatus) {
 document.getElementById(aDivName).style.display = showStatus ? 'block' : 'none';
} 
//-->
</script>

</head>
<body>
<input type="radio" name="r1" checked="true" onclick="show('gruppo1',true)">Mostra

<input type="radio" name="r1"                onclick="show('gruppo1',false)">Nascondi



<div id="gruppo1">
<table summary="">
<tr>
 <td>
  
 </td>
</tr>
<tr>
 <td>
  <form action="pippo.html" method="post">
	 Nome<input type="text" name="nome" />

	 Cognome<input type="text" name="cognome" />

	 <input type="submit" value="Invio">
	</form>
 </td>
</tr>
</table>
</div>
</body>
</html>