Complete the search function in the html page

 <div class="container" style="z-index: 999" id="searchDiv">
        <div class="keyword-search">
            Search for:
            <input id="key" type="text" style="width: 200px;" placeholder="Keyword" />
            <a href="javascript:void(0);" class="prev" onclick='wordSearch(1)'><i class="c-icon"></i></a>
            <a href="javascript:void(0);" class="next" onclick='wordSearch()'><i class="c-icon"></i></a>
        </div>
    </div>

  <script>//Search function var oldKey0 = "";
        var index0 = -1;var oldCount0 = 0;
        var newflag = 0;
        var currentLength = 0;
        function wordSearch(flg) {
            var key = $("#key").val(); //Get key valueif (!key) {
                return; //Exit if key is empty}
            getArray();
            focusNext(flg);
        }
        function focusNext(flg) {
            if (newflag == 0) {//If new search, index is cleared index0 = 0;
            }
            if (!flg) {
                if (oldCount0 != 0) {//If there is still searching if (index0 < oldCount0) {//If the left side is not finished, go to the left focusMove(index0);
                        index0++;
                    } else if (index0 == oldCount0) {//All done index0 = 0;
                        focusMove(index0);
                        index0++;
                    }
                    else {
                        index0 = 0; //Not confirmed focusMove(index0);
                        index0++;
                    }
                }
            } else {
                if (oldCount0 != 0) {//If there is still searching if (index0 <= oldCount0 && index0 > 0) {//If the left side is not finished, go to the left index0--;
                        focusMove(index0);
                    } else if (index0 == 0) {//All done index0 = oldCount0;
                        index0--
                        focusMove(index0);
                    }
                }
            }
        }
        function getArray() {
            newflag = 1;
            $(".contrast .result").removeClass("res");
            var key = $("#key").val(); //Get key valueif (!key) {
                oldKey0 = "";
                return; //Exit if key is empty}
            if (oldKey0 != key || $(".current").length != currentLength) {
                //Reset index0 = 0;
                var index = 0;
                $(".contrast .result").each(function () {
                    $(this).replaceWith($(this).html());
                });
                pos0 = new Array();
                if ($(".contrast-wrap").hasClass("current")) {
                    currentLength = $(".current").length;
                    $(".current .contrast").each(function () {
                        $(this).html($(this).html().replace(new RegExp(key, "gm"), "<span id='result" + (index++) + "' class='result'>" + key + "</span>")); // replace });
                } else {
                    $(".contrast-wrap").addClass('current');
                    currentLength = $(".current").length;
                    $(".contrast").each(function () {
                        $(this).html($(this).html().replace(new RegExp(key, "gm"), "<span id='result" + (index++) + "' class='result'>" + key + "</span>")); // replace });
                }
                //$("#key").val(key);
                oldKey0 = key;
                //$(".contrast .result").each(function () {
                // $(this).parents('.contrast-wrap').addClass('current');
                // pos0.push($(this).offset().top);
                //});
                // pos0.push($(".contrast .result:eq(2)").offset().top - $(".contrast .result:eq(2)").parents(".contrast").offset().top);
                oldCount0 = $(".contrast .result").length;
                newflag = 0;
            }
        }
        function focusMove(index0) {
            $(".contrast .result:eq(" + index0 + ")").parents('.contrast-wrap').addClass('current');
            $(".contrast .result:eq(" + index0 + ")").addClass("res");
            var top = $(".contrast .result:eq(" + index0 + ")").offset().top + $(".contrast .result:eq(" + index0 + ")").parents(".contrast").scrollTop();
            var intop = top - $(".contrast .result:eq(" + index0 + ")").parents(".contrast").offset().top;
            $(".contrast .result:eq(" + index0 + ")").parents(".contrast").animate({ scrollTop: intop }, 200);
            if ($(".contrast .result:eq(" + index0 + ")").parents(".contrast").scrollTop() == 0) {
                $("html, body").animate({ scrollTop: top - 200 }, 200);
            } else {
                $("html, body").animate({ scrollTop: $(".contrast .result:eq(" + index0 + ")").parents(".contrast").offset().top - 200 }, 200);
            }
        }
        $('#key').change(function () {
            if ($('#key').val() == "") {
                index0 = 0;
                $(".contrast .result").each(function () {
                    $(this).replaceWith($(this).html());
                });
                oldKey0 = "";
            }
        });
    </script>