<!DOCTYPE html>
<html>
<head>
<style>
button {
position: absolute;
}
button#b1 {
top: 20%; left: 25%;
nav-index: 1;
nav-right: #b2; nav-left: #b4;
nav-down: #b2; nav-up: #b4;
}
button#b2 {
top: 40%; left: 50%;
nav-index: 2;
nav-right: #b3; nav-left: #b1;
nav-down: #b3; nav-up: #b1;
}
button#b3 {
top: 70%; left: 25%;
nav-index: 3;
nav-right: #b4; nav-left: #b2;
nav-down: #b4; nav-up: #b2;
}
button#b4 {
top: 40%; left: 0%;
nav-index: 4;
nav-right: #b1; nav-left: #b3;
nav-down: #b1; nav-up: #b3;
}
</style>
</head>
<body>
<button id="b1">Button 1</button>
<button id="b2">Button 2</button>
<button id="b3">Button 3</button>
<button id="b4">Button 4</button>
<p><b>Note:</b> The nav- properties are only supported in Opera 12. This property is deprecated in newer versions of Opera. Hold down the Shift key while navigating with the arrow keys.</p>
</body>
</html>