Un petit ex peut-être pour la version tout en js:
(Ne fonctionne qu'avec IE, à toi de l'adapter pour qu'il fonctionne aussi avec les autres browsers...)
<html>
<head>
<script>
lastDisplayed = "traitement1";
function display(aNumber)
{
document.getElementById(lastDisplayed).style.visibility="hidden";
document.getElementById("traitement"+parseInt(aNumber)).style.visibility="visible";
lastDisplayed = "traitement"+parseInt(aNumber);
}
</script>
</head>
<body>
<form action="nextHtmlPage.html" method="post">
<input type="radio" name="group1" value="1" onClick="display(1);"> Enter only your name<br>
<input type="radio" name="group1" value="2" onClick="display(2);"> Enter name, firstname and age<br>
<input type="radio" name="group1" value="3" onClick="display(3);"> Enter what you want<br>
<br>
<div style="position:relative;top:0">
<div id="traitement1" style="visibility:hidden;position:absolute;top:0">
Name: <input type="text" value="Enter your name" name="TextField"><br>
<input type="submit">.
</div>
<div id="traitement2" style="visibility:hidden;position:absolute;top:0">
Name: <input type="text" value="Enter your name" name="nameTextField"><br>
Firstname: <input type="text" value="Enter your firstname" name="firstnameTextField"><br>
Age: <input type="text" value="Enter your age" name="ageTextField"><br>
<input type="submit">.
</div>
<div id="traitement3" style="visibility:hidden;position:absolute;top:0">
Comments: <input type="text" value="Enter what you want" name="commentTextField"><br>
<input type="submit">.
</div>
</div>
</form>
</body>
</html>