V1.0.0/2149

simple trick rather than using switch po, you can change id of #filter-bound to id #filter-hardbound po.
This part `<label class="btn btn-primary" id="filter-bound">` change to `<label class="btn btn-primary" id="filter-hardbound">`

then you can use this code
```
filter = $("#book-filter").val().toLowerCase();
$("#filter-" + filter).addClass("active");
```

Remember to change also those uses `filter-bound` if ever you used this trick po. :bow: