JQuery
Example
HTML (index.html)
<html>
<head>
<title>Button Magic</title>
<link rel='stylesheet' type='text/css' href='stylesheet.css'/>
<script type='text/javascript' src='script.js'></script>
</head>
<body>
<div><br/><strong>Click Me!</strong></div>
</body>
</html>
CSS (stylesheet.css)
div {
height: 60px;
width: 100px;
border-radius: 5px;
background-color: #69D2E7;
text-align: center;
color: #FFFFFF;
font-family: Verdana, Arial, Sans-Serif;
opacity: 0.5;
}
JavaScript (script.js)
$(document).ready(function(){
$('div').mouseenter(function(){
$('div').fadeTo('fast', 1.0);
});
$('div').mouseleave(function(){
$('div').fadeTo('fast', 0.5);
});
});