<?php if (is_home()) {
query_posts("posts_per_page=4");
while(have_posts()) : the_post(); ?>
<h2><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h2>
<?php the_post_thumbnail('featured-obiavi'); ?>
<?php the_excerpt(); ?>
<?php endwhile; }?>
add_theme_support('post-thumbnails');
set_post_thumbnail_size(150, 150, true);
add_image_size('featured-obiavi', 350, 200, true);