<form method="get" id="searchform" action="<?php echo esc_url( home_url( '/' ) ); ?>/">
    <div>
        <input type="text" value="<?php echo esc_attr( get_search_query() ); ?>" name="s" id="s" />
        <input type="submit" id="searchsubmit" value="<?php esc_attr_e('Search','TidalForce'); ?>" />
    </div>
</form>