BWL Knowledge Base Manager Simple Search Box

add_shortcode('bkb_simple_search', 'bkb_simple_search');

function bkb_simple_search(){

    $output = '<form action="'.esc_url(home_url('/')).'" id="search-form" class="search-form" role="form" method="get">

                    <div class="input-group">
                        <input type="text" class="form-control search-query" name="s" placeholder="'.__('Search', 'knowledgedesk').'" value="'.esc_attr(get_search_query()).'">
                        <span class="input-group-addon"><i class="fa fa-search"></i></span>
                        <input type="hidden" name="post_type" value="bwl_kb">
                    </div>

                    <input type="hidden" value="'.__('submit', 'knowledgedesk') .'" />

                    </form> <!-- end #search-form  -->';


    return $output;
}