Media Library image into its post ?

How to display an image from the Media Library into its post ?

I’ve tried:
<?php
$image = get_post_meta($post->ID, ‘image’, $single = true);
$image_alt = get_post_meta($post->ID, ‘image alt’, $single = true);
if (!empty($image))
{
?>
<img src=”<?php echo $image; ?>” alt=”<?php if(empty($image_alt)) { echo $image_alt; } else { echo the_title(); } ?>” class=”left-image” width=”142″/>
<?php
}
?>

but it’s not working…