adding a photo to blog posts unique to each author

What I’m trying to do is display the author name with a photo of the author next to their respective blog entries.

The following code is in the loop. I’m pretty green with PHP, so I may not be approaching this from the best angle. I have bolded the code that I wrote (the rest if from the wordpress support documentation).

<?php
if(get_query_var('author_name')) :
    $curauth = get_userdatabylogin(get_query_var('author_name'));
else :
    $curauth = get_userdata(get_query_var('author'));
endif;
if($curauth=="chimpact")
{
echo "<img src=\"images/cheryl-125x125.jpg\">";
}
?>
	<p>Written by:
<?php the_author_posts_link(); ?></p>