convert jquery code to javascript

HI,
I need to convert the following code in jquery into pure javascript :

$(".clock-input").keyup(function(e) {
        if (e.keyCode == 38 || e.keyCode == 40)
            return;
        $(".clock-drop-down").hide();
        var text = $(this).val().toLowerCase();
                $(".clock-drop-down").html(listHtml);
                $(".clock-drop-down").show();
            }

            $(".clock-autocompleteoption").on('mouseover', function() {
                $(".clock-autocompleteoption").removeClass("clock-selectedoption");
                $(this).addClass("clock-selectedoption");
            });

            $(".clock-autocompleteoption").on('click', function() {
                $('.clock-drop-down').hide();
                var jid = $(this).data('id');
                $('.clock-input').val($(this).text());
                $('.clock-filter').trigger('clock:click', jid);
            });
        }
    });

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Thanks