Det her kan gøre hvad du søger:
<!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>Untitled Page</title>
<script type="text/javascript">
var formOldValues = new Array();
function enableValidation()
{
var myForm = document.getElementById("myForm");
var fields = myForm.getElementsByTagName("input");
for (var i = 0; i < fields.length; i++)
{
var field = fields.item(i);
if (field.type == "text" && field.className.indexOf("NoValidate") < 0)
{
field.onkeyup = function () { toggleButtons(this); };
formOldValues[field.name] = field.value;
}
}
}
function toggleButtons(caller)
{
if (formOldValues[caller.name] != caller.value)
{
var myButtons = document.getElementById("FormButtons");
myButtons.style.display = "";
}
}
</script>
</head>
<body onload="enableValidation();">
<form id="myForm" action="">
<table border="0">
<tr>
<td>
First name:
</td>
<td>
<input type="text" name="FirstName" class="InputField" />
</td>
</tr>
<tr>
<td>
Last name:
</td>
<td>
<input type="text" name="LastName" class="InputField" />
</td>
</tr>
<tr>
<td>
Age:
</td>
<td>
<input type="text" name="Age" class="InputField NoValidate" />
</td>
</tr>
<tr id="FormButtons" style="display: none;">
<td colspan="2">
<input type="submit" value="Submit" />
</td>
</tr>
</table>
</form>
</body>
</html>
De felter du ikke vil have valideret, giver/tilføjer du "NoValidate" i [/i]class[/i] attributten (uden "").
OleBole har sikkert nogle indspark til ovenstående.. Han er lidt hård til det der Web 2.0 :)