$old_picture = mysqli_real_escape_string($dbc, trim($_POST['old_picture']));
    $new_picture = mysqli_real_escape_string($dbc, trim($_FILES['new_picture']['name']));
    $new_picture_type = $_FILES['new_picture']['type'];
    $new_picture_size = $_FILES['new_picture']['size'];
    list($new_picture_width, $new_picture_height) = getimagesize($_FILES['new_picture']['tmp_name']);
    $error = false;

    // Validate and move the uploaded picture file, if necessary
    if (!empty($new_picture)) {
      if ((($new_picture_type == 'image/gif') || ($new_picture_type == 'image/jpeg') || ($new_picture_type == 'image/pjpeg') ||
        ($new_picture_type == 'image/png')) && ($new_picture_size > 0) && ($new_picture_size <= MM_MAXFILESIZE) &&
        ($new_picture_width <= MM_MAXIMGWIDTH) && ($new_picture_height <= MM_MAXIMGHEIGHT)) {
        if ($_FILES['file']['error'] == 0) {
          // Move the file to the target upload folder
          $target = MM_UPLOADPATH . basename($new_picture);
          if (move_uploaded_file($_FILES['new_picture']['tmp_name'], $target)) {
            // The new picture file move was successful, now make sure any old picture is deleted
            if (!empty($old_picture) && ($old_picture != $new_picture)) {
              @unlink(MM_UPLOADPATH . $old_picture);
            }
          }
          else {
            // The new picture file move failed, so delete the temporary file and set the error flag
            @unlink($_FILES['new_picture']['tmp_name']);
            $error = true;
            echo '<p class="error">Sorry, there was a problem uploading your picture.</p>';
          }
        }
      }
      else {
        // The new picture file is not valid, so delete the temporary file and set the error flag
        @unlink($_FILES['new_picture']['tmp_name']);
        $error = true;
        echo '<p class="error">Your picture must be a GIF, JPEG, or PNG image file no greater than ' . (MM_MAXFILESIZE / 1024) .
          ' KB and ' . MM_MAXIMGWIDTH . 'x' . MM_MAXIMGHEIGHT . ' pixels in size.</p>';
      }
    }