Спасибо!
<head>
<script language="JavaScript">
function show(el) {
ells = document.getElementById(el);
ells.style.display = (ells.style.display == 'none')? 'block': 'none';
}
</script>
</head>
<body>
<form action="/stuff/start-with-ajax/text/index.php" method="POST">
<input type="Button" id="Button1" name="Button1" value="Ok" onClick="show('form2')" />
</form>
<form name="form2" style="display: none;">
<pre id="TextForm2">Ôîðìà2</pre>
</form>
</body>
</html>