Show user thumbnail

[ale89]

Hi everyone!
On the main page of my web page displays the latest tracks created, which shows the title of the subject, who did it, the category in which I believe and the facade.
But now I would like to show your profile picture thumbnail which takes you to their profile.
I have created a folder called members in which when a user logs folder is created with the id. Example: members / id and the folder id is your profile photo.
This is my php code:

<?php

include('./global.php');

$sql = "SELECT
            categories.cat_id,
            categories.cat_name,
            categories.cat_description,
            COUNT(topics.topic_id) AS topics
        FROM
            categories
        LEFT JOIN
            topics
        ON
            topics.topic_id = categories.cat_id
        GROUP BY
            categories.cat_name, categories.cat_description, categories.cat_id";

$result = mysql_query($sql);
if(!$result)
{
    echo 'Unable to display the latest topics, please try again later.';
}
else
{
    if(mysql_num_rows($result) == 0)
    {
        echo 'There are no categories.';
    }
    else
    {
        echo '
         
<div class="group" id="main-content">
    

      <div class="content-container">
    
                <div class="view view-blog view-id-blog view-display-id-page_1 view-dom-id-1 content-section">
    
  
  
     
        ';
       
     
        while($row = mysql_fetch_assoc($result))
        {                
                
                //fetch last topic for each cat
                    $topicsql = "SELECT
                                    topic_id,
                                    topic_subject,
                                    topic_date,
                                    topic_cat,
                                    topic_by,
                                    users.id,
                                 users.username
                                FROM
                                    topics
                                 
                                 LEFT JOIN
                        users
                    ON
                        topics.topic_by = users.id
                                WHERE
                                    topic_cat = " . $row['cat_id'] . "
                                ORDER BY
                                    topic_date
                                DESC
                                LIMIT
                                    5";
                                
                    $topicsresult = mysql_query($topicsql);
                
                    if(!$topicsresult)
                    {
                        echo 'Unable to display the latest news ..';
                    }
                    else
                    {
                        while($topicrow = mysql_fetch_assoc($topicsresult))
                        
   echo '
                          <div class="view-content">
        <div class="views-row views-row-1 views-row-odd views-row-first">
    <div class="post group">

  <div class="post-thumbnail">
    <div class="picture">
  <a href="profile/?id='. $topicrow['id'] .'">';?><img src="members/<?php echo "$id"; ?>/pic1.jpg" class="user-picture" /><?
  echo '
  </a></div>
  
  </div>
    <div class="group">
        <div class="post-meta">
            <h4 class="post-title"><a href="topic.php?id=' . $topicrow['topic_id'] . '">' . $topicrow['topic_subject'] . '</a></h4>
              <span>Por <a href="profile/?id='. $topicrow['id'] .'"> '. $topicrow['username'] .'</a> el '.date('d-m-Y H:i', strtotime($topicrow['topic_date'])).'</span>

            <div>
      <ul class="links inline"><li class="taxonomy_term_3 first last"><a href="category.php?id=' . $row['cat_id'] . '">' . $row['cat_name'] . '</a></li>
</ul>    </div>
      </div>
    <div class="post-body">
    <p>content...</p>
  </div>
  </div>

<div>
  </div>
</div>
  </div>
';

   
    
                            
                        }
        } 
        
        echo '
        
  
</div>       </div>

    </div> 
        ';
    }
}
?>

Where's members / <?php echo "$ id"?> Show the user's photo.
Any ideas or suggestions how to do it I thank you all!
Thank you very much and greetings!:)