If you have a container and two sub containers, you can do like this
jQuery
$("#previousbutton").click(function() {
$("#form_sub_container1").show();
$("#form_sub_container2").hide(); })
$("#nextbutton").click(function() {
$("#form_container").find(":hidden").show().next();
$("#form_sub_container1").hide();
})
HTML
<div id="form_container">
<div id="form_sub_container1" style="display: block;">
</div>
<div id="form_sub_container2" style="display: none;">
</div>
</div>