title: echo variable into input type checkbox value displaying empty even though I confirm it has value
body: <p>I am displaying row_id and checkboxes so the user can check which row to export from the database. </p>
  
  <p>I confirm that $row_id has value because it does display on the screen immediately before I try to use the  command. </p>
  
  <p>The checkboxes also appear and the user is able to check them. </p>
  
  <p>After clicking SUBMIT, I display the count of check_list[] and the value of check_list[]. Interestingly, the count displays a value of 2 indicating correctly that the user checked 2 boxes, but the value is not being captured or displayed.</p>
  
  <p>Here is the code that I am having trouble with. The value is displaying blank instead of the value of $row_id.</p>
  
  <pre><code>$row_id = $row['id'];
  echo '&lt;td&gt;'. $row_id ;
  echo '&lt;input type="checkbox" name="check_list[]" value="&lt;?php echo !empty($row_id)?$row_id;?&gt;" ';
  </code></pre>