wordpress: use post-thumbnail if set?

hey guys, i hope there are a few wordpress experts out t开发者_开发百科here that can help me with ths. i'm using:

the_post_thumbnail('medium');

to view a post-thumbnail that can be set for every post in the backend.

however, if there is no postthumbnail set i want to print out a different image. any idea how i can check the function to find out if a post-thumbnail for a specific post is set?

thank you

<?php if( get_post_thumbnail_id() ):
    the_post_thumbnail( 'medium' );
else: ?>
    <img src="some_other_image.png" alt="" />
<?php endif; ?>

The above code will work fine, Though i think the write way would to show your post would be like this:

// Wrap it
if  ( function_exists("has_post_thumbnail") && has_post_thumbnail() ) {
    the_post_thumbnail( 'medium' );
} else {
    // If there is no thumb, show a default one.
    echo '<img src="'.get_bloginfo("template_url").'/images/default-post-thumbnail.gif" alt="" />';
}

Not much difference, just the wrapper.

Source: How to use Post Thumbnails Feature in Wordpress!