<!-- start main nav -->
	<?php

        $defaults = array(
                    'theme_location'  => 'main-menu',
                    'menu'            => '',
                    'container'       => 'ul',
                    'container_class' => '',
                    'menu_class'      => '',
                    'menu_id'         => '',
                    'echo'            => true,
                    'fallback_cb'     => 'show_top_menu',
                    'before'          => '',
                    'after'           => '',
                    'link_before'     => '',
                    'link_after'      => '',
                    'items_wrap'      => '%3$s',
                    'depth'           => 0,
                    'walker'          => new description_walker
                        );

         $athers = array(
                    'theme_location'  => 'top-menu',
                    'menu'            => 'div',
                    'container'       => '',
                    'container_class' => '',
                    'menu_class'      => '',
                    'menu_id'         => '',
                    'echo'            => true,
                    'fallback_cb'     => 'show_top_menu',
                    'before'          => '',
                    'after'           => '',
                    'link_before'     => '',
                    'link_after'      => '',
                    'items_wrap'      => '%3$s',
                    'depth'           => 0,
                    'walker'          => '',
                        );
        

        if(has_nav_menu('main-menu')) {
            wp_nav_menu( $defaults );
		}
        else if(has_nav_menu('top-menu')){
            wp_nav_menu( $athers );
        }
        else {
            echo ('<li><a href="#">No menu assigned!</a></li>');
        }
                        ?>