YUI().use("transition", "panel", function(Y) {

var openBtn = Y.one('#openButton'),

panel = new Y.Panel({

srcNode: "#panelContent",

width:330,

centered:true,

modal:true,

visible:false,

zIndex: 5,

buttons: [

{

value: "Close the panel",

action: function(e) {

e.preventDefault();

panel.hide();

},

section: "footer"

}

],

render:true

}),

bb = panel.get('boundingBox');

bb.setStyles({

"opacity": 0

});

panel.on('visibleChange', toggleAnimation);

openBtn.on('click', function(e) {

panel.show();

});

function toggleAnimation (e) {

if (e.newVal) {

bb.transition({

duration: 1,

opacity: 1

});

}

else {

bb.transition({

duration: 1,

opacity: 0

});

}

}

});