SOLVED How to clear the values of a smartselect?

I can´t clear/remove the selected values in a smartselect that I have, I have looked at the docs but I can´t get it to work, so any input appreciated, thanks.

My select that I have now.

    <a href="#" class="item-link smart-select smart-select-init" data-open-in="popover">
        <select id="fargerna" name="fargerna" class="fargerna" multiple>
          <optgroup label="Välj färger.">
          <%do until rs1.eof%>
          <option value="<%=rs1("farg")%>"><%=rs1("farg")%></option>
        <div class="item-content item-input" style="padding-left: 0px;">
          <div class="item-inner">
            <div class="item-title">Välj färg</div>


Thanks Vladimir. Got it working.