ajax jquery event key code bind key down

var jq4u = 'jquery';
for (n = 0; n & lt; = 5; n++) {
    $('#' + id).append('<div class=&quot;bigcolordiv key-' + jq4u[n] + '&quot; style=&quot;background-color:blue;&quot;>' + jq4u[n] + '</div>');
}

$(W).bind('keydown', function (key) {
    //jquery, 74, 81, 85, 69, 82, 89
    var keycode;
    if (key == null) {
        keycode = event.keyCode;
    } else {
        keycode = key.keyCode;
    }
    $('#' + id + ' .key-' + String.fromCharCode(keycode).toLowerCase()).toggleClass('orangebg');
});