How to do this pop up login Box

I’d like to implement login modal box feature on top right screen on www.dropbox.com

I know they use jQuery, but I am not sure how.

Can you help me explain mechanism used to do this login popup box? Especially, how it can be used under Yii framework.

Thank you!

The part of login box id created using Div and is made Hidden.

When someone clicks on Login link it is made visible.

if




<a href="" id="login">Login</a>

<div id="login-box" style="display:hidden"></div>



then




$("#login").click(function(){

$("#login-box").toggle(400);

});