Javascript mouse-over menu

I'm looking for a pre-made script that would do the same thing as:

http://www.kontera.com/

When you hover over the "Log In" text in the top navigation bar.


Where would I go to find something like this?

 

I dont know where to find this script, but it is not hard to write it...

They have hidden div on the page. The div is absolute positioned and have bigger z-index:

#toplogin_box {
    background: url("../images/frontpage_window.png") no-repeat scroll 0 0 transparent;
    height: 89px;
    margin-left: 607px;
    margin-top: 23px;
    padding-top: 21px;
    position: absolute;
    text-align: center;
    width: 330px;
    z-index: 3;
}

Code (markup):

When user do mouseover over hyperlink then this div is displayed. On mouseout is hidden again.