fade a page in with jquery after a button is clicked

fade a page in with jquery after a button is clicked

with this jquery i can fade the page in after it loads:
<script type="text/javascript">
$(function() {
$('body').hide().fadeIn(1000);
});
</script>
now what i want to do is have it that function happen after a button is
clicked. for example, when the user goes to the page, there would be a
window with a clickable button. after the button was clicked then it would
do that fade in jquery loading the page with a fade in. i was thinking
that it would be some kind of form, but the problem is it needs to hide
the body when the page is loaded, and then fade in to the body after the
button is clicked.