File index.php của theme Wordpress

<?php get_header() ?>
    <div id="blog" class="container_12">
        <div class="grid_12 omega" id="main-menu">
            <?php
            wp_nav_menu(array(
                'theme_location' => 'main-menu'
                ));
            ?>
        </div><!--End main-menu-->
        <div id="main-content" class="grid_8 alpha">
            <div class="post">
                <?php if(have_posts()): ?><?php while (have_posts()): the_post(); ?>
                    <div class="post_info">
                        <?php the_post_thumbnail( $size = 'thumbnail', array (
                            'class' => "homepage-thumbnail",
                        ) );?>
                        <h3><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h3>
                        <p class="meta-data">
                            Đăng bởi&nbsp;<?php the_author(); ?>&nbsp;ngày&nbsp;<?php the_date(); ?>&nbsp;trong&nbsp;<?php the_category( $separator = ',') ;?>
                        </p>
                        <?php the_excerpt();?>
                    <?php endwhile; ?>
                </div><!--End entry-->
                <div id="navigation">
                    <?php posts_nav_link( $sep = '', $prelabel = 'Trang trước', $nxtlabel = 'Trang sau' );?>
                </div>
                <?php endif;?>
            </div><!--end post-->
        </div><!--End main-content-->
            <div class="grid_4 omega" id="sidebar">
                <?php if ( !function_exists('dynamic_sidebar')
                || !dynamic_sidebar('sidebar') ) : ?>
                <?php endif; ?>
            </div>
    </div>
            <?php get_footer(  );?>