<button id="hide">hide</button>

<button id="show">show</button>

<div class="demo"><p>lorem ipsum dolor sit</p></div>

<script type="text/javascript">

YUI().use('transition', 'node-event-delegate', function(Y) {

Y.delegate('click', function(e) {

var buttonID = e.currentTarget.get('id'),

node = Y.one('.demo');

if (buttonID === 'show') {

node.show(true);

} else if (buttonID == 'hide') {

node.hide(true);

}

}, document, 'button');

});

</script>