PHP:
<html>
<head>
<script type="text/javascript">
function whichButton()
{
alert(event.keyCode)
}
</script>
</head>
<body onkeyup="whichButton()">
</body>
PHP:
<html>
<head>
<script type="text/javascript">
function whichButton()
{
alert(event.keyCode)
}
</script>
</head>
<body onkeyup="whichButton()">
</body>