jQuery.fn.filterByText = function(textbox, selectSingleMatch) {
    return this.each(function() {
        var select = this;
        var options = [];
        $(select).find('option').each(function() {
            options.push({
                value: $(this).val(),
                jQuery.fn.filterByText = function(textbox, selectSingleMatch) {
                    return this.each(function() {
                        var select = this;
                        var options = [];
                        $(select).find('option').each(function() {
                            options.push({
                                value: $(this).val(),
                                text: $(this).text()
                            });
                        });
                        $(select).data('options', options);
                        $(textbox).bind('change keyup', function() {
                            var options = $(select).empty().data('options');
                            var search = $.trim($(this).val());
                            var regex = new RegExp(search, "gi");

                            $.each(options, function(i) {
                                var option = options[i];
                                if (option.text.match(regex) !== null) {
                                    $(select).append(
                                    $('<option>').text(option.text).val(option.value));
                                }
                            });
                            if (selectSingleMatch === true && $(select).children().length === 1) {
                                $(select).children().get(0).selected = true;
                            }
                        });
                    });
                };

                $(function() {
                    $('#sel').filterByText($('#textbox'), true);
                });
                text: $(this).text()
            });
        });
        $(select).data('options', options);
        $(textbox).bind('change keyup', function() {
            var options = $(select).empty().data('options');
            var search = $.trim($(this).val());
            var regex = new RegExp(search, "gi");

            $.each(options, function(i) {
                var option = options[i];
                if (option.text.match(regex) !== null) {
                    $(select).append(
                    $('<option>').text(option.text).val(option.value));
                }
            });
            if (selectSingleMatch === true && $(select).children().length === 1) {
                $(select).children().get(0).selected = true;
            }
        });
    });
};

$(function() {
    $('#sel').filterByText($('#textbox'), true);
});

Setting Validate Copy Format

#a{
  display:inline-block;
}
#result{
  display:inline-block;
}

Setting Validate Copy Format

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<title>filterByText example</title>
</head>
<body>
<input id="textbox" type="text" /><br />
<ul id="se">
  <li value="1">1</li>
  <option value="1234567890">1234567890</option>
  <option value="better">better</option>
  <option value="world">world</option>
  <option value="goodly deeds">goodly deeds</option>
</select>
</body>
</html>

Copy Format

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