CSS3 - JavaScript OnMouseOver

<html>
<head>
<style type="text/css">
#divB {
    display: none;
}

#divA:hover + #divB {
    display:  block;
}
</style>
</head>
<body>

<div id="divA">
    :-) :-) :-) :-) :-) :-) :-) :-)
</div>
<div id="divB">
    :-D :-D :-D :-D :-D :-D :-D :-D
</div>

</body>
</html>