Multi nested if conditions & custom values in blog posts

Hi there,

I am trying to pull images into my wordpress page using 3 if conditions which looks for 2 different custom values in my blog post.

In layman's words,
[IF] custom_field1="A", echo="B" [ELSE]
[IF] custom_field2="C", echo="D" [ELSE]
[IF] image_exists_in_post, echo="E" [ELSE]
echo="F"
[END]

Now here is my proper PHP code,

<?php query_posts('showposts=1&cat=4'); ?>
<?php while (have_posts()) : the_post(); ?>
<?php $id =$post->ID;
$the_content =$wpdb->get_var("SELECT post_content FROM $wpdb->posts WHERE ID = $id");
$pattern = '!<img.*?src="(.*?)"!';
preg_match_all($pattern, $the_content, $matches);
$image_src = $matches['1'][0];
?>            

<div>

<?php $variable = get_post_custom_values("cValue"); if (isset($variable[0])) { ?>
<img src="<?php $variable = get_post_custom_values("cValue"); echo $variable[0]; ?>
<?php } else {?>						

<?php $values = get_post_custom_values("Image"); if (isset($values[0])) { ?>
<img src="<?php $values = get_post_custom_values("Image"); echo $values[0]; ?>
<?php } else {?>						

<?php if($image_src != '') { ?>
<img src="<?php echo bloginfo('template_url'); ?>
<?php } else {?>

<img src="<?php echo bloginfo('template_url'); ?>/images/no-attachment_headline.gif">           

<?php }?>
<?php }?>
<?php }?>

</div>

<?php endwhile; ?>
<?php wp_reset_query(); ?>

I’ve omitted some of my original code just to save some confusion.
Is it a simple problem of syntax issues?