[Plugin: Timthumb] Image in post

Good Morning,
I want to auto crop image in the posts using timthumb and zoom out with lightbox plugin. I tried to use this code
<a href="<?php the_permalink() ?>" rel="bookmark"><img src="<?php bloginfo('template_directory'); ?>/includes/timthumb.php?src=<?php get_thumbnail($post->ID, 'full'); ?>&h=100&w=100&zc=1" alt="<?php the_title(); ?>" /> </a>
but is connected with post link and not with relative original size image. Can you help me?

Thank you so much.
MaNu_RM