Event JavaScript when Esc on click?

How to ma开发者_C百科ke the event when the Esc key is pressed; please give me an example of an alert ();.

---

document.body.onkeyup = function(e){
    if(e.keyCode == 27){
        alert('Yay');
    }
}

---

if your interested in using jquery, check this code

<script type="text/javascript">

$("CssSelector").on("keyup", HandleKeyEvent(e));

function HandleKeyEvent(e)
{
    if ( e.keyCode == 27 && e.key == "Escape" )
    {
        //--> Do Something
        alert("It Works");
    }

} );

</script>

Sorry I have just realized that this is an old question from 2011.