function get_terms_grades_dropdown($taxonomies, $args)
    {
        global $search_values;

        $myterms = get_terms($taxonomies, $args);
        $output = "";
        foreach ($myterms as $term) {
            $root_url = get_bloginfo('url');
            $term_taxonomy = $term->grades;
            $term_slug = $term->slug;
            $term_name = $term->name;
            $value = $term->term_id;
            if ($search_values['grades'] == $term->slug) {
                $selected = "selected='selected'";
            } else {
                $selected = '';
            }
            $output .= "<option value='" . $value . "' " . $selected . ">" . $term_name . "</option>";
        }

        return $output;
    }

if ($search_values['grades'] == $term->slug) {
    $selected = "selected='selected'";
}