Custom Taxonomy and Custom Post Types

Hello,
I am having a problem with custom post type and custom taxonomies. I created a custom post type called ‘galleries’ and taxonomies named ‘gallery_type’. And I have created a page called Gallery in which i loaded all the posts from galleries. And then I have created ‘garden’ & ‘house’ taxonomy terms and assigned 3-3 posts to each ‘garden’ & ‘house’. And I linked the taxonomy terms ‘garden’ and ‘house’ as sub-menu to gallery which is my current parent. I want to display the posts in their respective terms. But it is not loading. What can I do ??
My code is: `
$tax = ‘gallery_type’;
$terms = get_the_terms($post->ID, $tax);
if($terms){
foreach($terms as $term){
$single = $term->name;
?>

<ul>
<?php
$args = array(‘post_type’=>’galleries’,
‘posts_per_page’=> -1,
‘tax_query’=>array(
array(‘taxonomy’=>’gallery_type’,
‘terms’=> $single)
),
‘order_by’=>’post_date’);
$query = new WP_Query($args);
if($query->have_posts()){
while($query->have_posts()):
$query->the_post();
$post_id = $post->ID;
?>
<li class=”thumb <?php echo $post_id; ?>” onclick=”changeContent(<?php echo $post_id; ?>);”>
<?php if(has_post_thumbnail())
the_post_thumbnail(‘gallery-thumb’);
?>

<?php
endwhile;
wp_reset_query();
}
else{
_e(‘No image found in gallery’,’bseep’);
}
`

Any fix???