Featured Image with captions

gistfile1.phtml

if ( ! function_exists( 'mytheme_entry_image' ) ) :
/**
 * Display an optional entry thumbnail.
 */
function mytheme_entry_image() {
	if ( ! has_post_thumbnail() ) {
		return;
	}
	$featured_image = get_post_thumbnail_id();
	$attachment_page = esc_url( get_attachment_link( $featured_image ) );
	$caption = get_post(get_post_thumbnail_id())->post_excerpt;
?>		
	<dl class="entry-image">
		<dt class="entry-image-container">
		<?php
			if ( ! is_singular() ) : ?>
				<a href="<?php echo esc_url( get_permalink() ); ?>" title="<?php echo esc_attr( get_the_title() ); ?>" rel="bookmark">
					<?php the_post_thumbnail( 'large' ); ?>
				</a><?php  
			else :  			  
				the_post_thumbnail( 'large' ); 
			endif;
		?>
			<a class="entry-image-more" href="<?php echo $attachment_page; ?>" title="<?php _e('Image details', 'sendtheme'); ?>">
				<?php _e('Image details', 'sendtheme'); ?>
			</a>
		</dt><!-- .entry-image-container -->
		<?php 
			// Show the hand-crafted image caption (if available)
			if ( trim( $caption ) ) : ?>
				<dd class="entry-image-caption">
					<?php echo wptexturize( $caption ); ?>
				</dd><!-- .entry-image-caption --><?php 
			endif; 
		?>
	</dl><!-- .entry-image --><?php
}
endif; // mytheme_entry_image