jquery regex fix table search

turkish character regex search jquery.js

    <input type="text" id="myInput" class="form-control mb5" placeholder="Sinav arayin...">

    <div style="overflow: auto; max-height: 250px">
        <table id="myTable">
            {% for exam in exams %}
                <tr>
                    <td width="1">
                        <input type="checkbox" name="examList[]" value="{{ exam.id }}">
                    </td>
                    <td>
                        {{ exam.code }} - {{ exam.name }}
                    </td>
                </tr>
            {% endfor %}
        </table>
    </div>

    <script type="text/javascript">

        function _fnEscapeRegex(sVal) {

            var letters = {
                "İ": "[İiIı]",
                "I": "[İiIı]",
                "Ş": "[ŞşSs]",
                "S": "[ŞşSs]",
                "Ğ": "[ĞğGg]",
                "G": "[ĞğGg]",
                "Ü": "[ÜüUu]",
                "U": "[ÜüUu]",
                "Ö": "[ÖöOo]",
                "O": "[ÖöOo]",
                "Ç": "[ÇçCc]",
                "C": "[ÇçCc]",
                "i": "[İiIı]",
                "ı": "[İiIı]",
                "ş": "[ŞşSs]",
                "s": "[ŞşSs]",
                "ğ": "[GgĞğ]",
                "g": "[GgĞğ]",
                "ü": "[ÜüUu]",
                "u": "[ÜüUu]",
                "ö": "[ÖöOo]",
                "o": "[ÖöOo]",
                "ç": "[ÇçCc]",
                "c": "[ÇçCc]"
            };

            var acEscape = ['/', '.', '*', '+', '?', '|', '(', ')', '[', ']', '{', '}', '\\', '$', '^', '-'];
            var reReplace = new RegExp('(\\' + acEscape.join('|\\') + ')', 'g');
            sVal = sVal.replace(reReplace, '\\$1');

            return sVal.replace(/(([İIŞSĞÜUÇÖiışsğüuçö]))/g, function (letter) {
                return letters[letter];
            });
        }

        String.prototype.turkishToLower = function(){
            var string = this;
            var letters = { "İ": "i", "I": "ı", "Ş": "ş", "Ğ": "ğ", "Ü": "ü", "Ö": "ö", "Ç": "ç" };
            string = string.replace(/(([İIŞĞÜÇÖ]))/g, function(letter){ return letters[letter]; })
            return string.toLowerCase();
        }
 
        $(document).ready(function () {

            $('#myTable tr').click(function (event) {
                if (event.target.type !== 'checkbox') {
                    $(':checkbox', this).trigger('click');
                }
            });

            $("#myInput").keyup(function () {

                _this = this;

                var keyword = $(_this).val().turkishToLower();
                keyword = _fnEscapeRegex(keyword);
                console.log(keyword);

                $.each($("#myTable tbody tr"), function () {


                    if ($(this).text().turkishToLower().match(new RegExp(keyword))) {

                        console.log($(this).text().turkishToLower());

                        $(this).show();
                    }
                    else {
                        $(this).hide();
                    }
                });
            });

        });


    </script>