js filter text

1<script>
2    $('input[name="search_field"]').on("keyup", function() {
3        filtrate($(this).val().toLowerCase());
4    });
5
6    function filtrate(searched) {
7        $(".filter-key > h3").filter(function() {
8            var isHidden = ($(this).text().toLowerCase().indexOf(searched) > -1) ? 'block' : 'none';
9            $('.filter-key').css('display', isHidden);
10        });
11    }
12</script>