switch(key) {
case 37:
$.keynav.goLeft();
break;
case 38:
$.keynav.goUp();
break;
case 39:
$.keynav.goRight();
break;
case 40:
$.keynav.goDown();
break;
case 13:
$.keynav.activate();
break;
}
function myFunction(event) {
var x = event.charCode;
document.getElementById("demo").innerHTML = "The Unicode value is: " + x;
}
<p>Keycode 13 is: </p>
<button>Enter</button>
<p>Press a key on the keyboard in the input field to get the Unicode character code of the pressed key.</p>
<b>You can test in below</b>
<input type="text" size="40" onkeypress="myFunction(event)">
<p id="demo"></p>
<p><strong>Note:</strong> The charCode property is not supported in IE8 and earlier versions.</p>