JavaScript Tutorial/Document/onkeydown
document.onkeydown
The onkeydown event handler specifies what should happen when any key is pressed when the Document object is in focus.
<html>
<head>
<script language="JavaScript1.2">
<!--
document.onkeydown = myKeyDownHandler;
function myKeyDownHandler(){
alert("A key down event took place within the document!");
}
-->
</script>
</head>
<body>
press a key within this document.
</body>
</html>