/**
  */
 function save_post_meta($post_id)
 {
     if (defined('DOING_AUTOSAVE') && DOING_AUTOSAVE) {
         return $post_id;
     }
     if (!current_user_can('edit_posts')) {
         return;
     }
     if (!isset($id)) {
         $id = (int) $post_id;
     }
     if (isset($_POST['assignment-subtitle'])) {
         if (isset($_POST['assignment-subtitle']) && $_POST['assignment-subtitle'] != '') {
             update_post_meta($post_id, "assignment-subtitle", stripslashes($_POST['assignment-subtitle']));
         } else {
             delete_post_meta($post_id, "assignment-subtitle");
         }
         if (isset($_POST['assignment-maximum-mark']) && $_POST['assignment-maximum-mark'] != '') {
             update_post_meta($post_id, "assignment-maximum-mark", stripslashes($_POST['assignment-maximum-mark']));
         } else {
             delete_post_meta($post_id, "assignment-maximum-mark");
         }
         if (isset($_POST['assignment-enable-textarea']) && $_POST['assignment-enable-textarea'] != '') {
             update_post_meta($post_id, "assignment-enable-textarea", stripslashes($_POST['assignment-enable-textarea']));
         } else {
             delete_post_meta($post_id, "assignment-enable-textarea");
         }
         if (isset($_POST['assignment-enable-attachment']) && $_POST['assignment-enable-attachment'] != '') {
             update_post_meta($post_id, "assignment-enable-attachment", stripslashes($_POST['assignment-enable-attachment']));
         } else {
             delete_post_meta($post_id, "assignment-enable-attachment");
         }
         if (isset($_POST['assignment-attachment-type']) && $_POST['assignment-attachment-type'] != '') {
             update_post_meta($post_id, "assignment-attachment-type", $_POST['assignment-attachment-type']);
         } else {
             delete_post_meta($post_id, "assignment-attachment-type");
         }
         if ($_POST['assignment-attachment-size'] > dt_get_upload_size()) {
             $attachment_size = 0;
         } else {
             $attachment_size = $_POST['assignment-attachment-size'];
         }
         if (isset($_POST['assignment-attachment-size']) && $_POST['assignment-attachment-size'] != '') {
             update_post_meta($post_id, "assignment-attachment-size", $attachment_size);
         } else {
             delete_post_meta($post_id, "assignment-attachment-size");
         }
         if (isset($_POST['assignment-course-evaluation']) && $_POST['assignment-course-evaluation'] != '') {
             update_post_meta($post_id, "assignment-course-evaluation", $_POST['assignment-course-evaluation']);
         } else {
             delete_post_meta($post_id, "assignment-course-evaluation");
         }
         if (isset($_POST['dt-assignment-course']) && $_POST['dt-assignment-course'] != '') {
             update_post_meta($post_id, "dt-assignment-course", $_POST['dt-assignment-course']);
         } else {
             delete_post_meta($post_id, "dt-assignment-course");
         }
     }
 }
    <div class="column one-sixth">
       <label><?php 
_e('Attachment Size (MB)', 'dt_themes');
?>
</label>
    </div>
    <div class="column five-sixth last">
		<?php 
$assignment_attachment_size = get_post_meta($post_id, "assignment-attachment-size", true);
?>
        <input id="assignment-attachment-size" name="assignment-attachment-size" class="large" type="number" value="<?php 
echo $assignment_attachment_size;
?>
" style="width:10%;" />
        <p class="note"> <?php 
_e('Set maximum size for attachment. Set it less than <strong>' . dt_get_upload_size() . 'MB</strong>. If you like to have more than <strong>' . dt_get_upload_size() . 'MB</strong>, than you have to make changes in php.ini file. ', 'dt_themes');
?>
 </p>
    </div>
    
</div>
<!-- Attachment Size End -->

<!-- Include In Course Evaluation -->
<div class="custom-box">

    <div class="column one-sixth">
       <label><?php 
_e('Include In Course Evaluation', 'dt_themes');
?>
</label>