button rearrangement after form_alter

i already tried setting different buttun weights for each but couldn't achieve the goal so may i post the true codes
in uc_cart.module. i had the following functions.

function uc_cart_view_form($form_state, $items = NULL) {
  $form['items'] = array(
    '#type' => 'tapir_table',
    '#tree' => TRUE,
  );

  $context = array(
    'revision' => 'themed-original',
    'type' => 'amount',
  );
  $i = 0;


  foreach ($items as $item) {
    $display_item = module_invoke($item->module, 'cart_display', $item);

    if (!empty($display_item)) {
      $form['items'][$i] = $display_item;
      //print_R($form['items'][$i]);

      $form['items'][$i]['image']['#value'] = uc_product_get_picture($display_item['nid']['#value'], 'cart');

      $description = $display_item['title']['#value'] . $display_item['description']['#value'];
      $form['items'][$i]['desc']['#value'] = $description;

      $form['items'][$i]['title']['#type'] = 'value';
      $form['items'][$i]['description']['#type'] = 'value';

      if (empty($display_item['qty'])) {
        $form['items'][$i]['qty'] = array(
          '#value' => '',

        );
      }

      $form['items'][$i]['total'] = array(
        '#value' => uc_price($display_item['#total'], $context),
        '#theme' => 'uc_cart_view_price',

      );
      $i++;
    }
  }

  $form['items'] = tapir_get_table('uc_cart_view_table', $form['items']);

  // If the continue shopping element is enabled...
  if (($cs_type = variable_get('uc_continue_shopping_type', 'link')) !== 'none') {
    // Setup the text used for the element.
    $cs_text = variable_get('uc_continue_shopping_text', '') ? variable_get('uc_continue_shopping_text', '') : t('Continue shopping');

    // Add the element to the form based on the element type.
    if (variable_get('uc_continue_shopping_type', 'link') == 'link') {
      $form['continue_shopping'] = array(
        '#value' => l($cs_text, uc_cart_continue_shopping_url()),
      );
    }
    elseif (variable_get('uc_continue_shopping_type', 'link') == 'button') {
      $form['continue_shopping'] = array(
        '#type' => 'submit',
        '#value' => $cs_text,
        '#submit' => array('uc_cart_view_form_submit'),

      );

      $form['continue_shopping_text'] = array(
        '#type' => 'hidden',
        '#value' => $cs_text,
      );
    }
  }

  // Add the control buttons for updating and proceeding to checkout.
  $form['update'] = array(
    '#type' => 'submit',
    '#value' => t('Update cart'),
    '#submit' => array('uc_cart_view_form_submit'),

  );
  if (variable_get('uc_checkout_enabled', TRUE)) {
    $form['checkout'] = array(
      '#type' => 'submit',
      '#value' => t('Checkout'),

      '#submit' => array('uc_cart_view_form_submit'),
    );
  }

  return $form;
}


function theme_uc_cart_view_form($form) {
  drupal_add_css(drupal_get_path('module', 'uc_cart') .'/uc_cart.css');

  $output = '<div id="cart-form-products">'
          . drupal_render($form['items']) .'</div>';

  foreach (element_children($form['items']) as $i) {
    foreach (array('title', 'options', 'remove', 'image', 'qty') as $column) {
      $form['items'][$i][$column]['#printed'] = TRUE;
    }
    $form['items'][$i]['#printed'] = TRUE;
  }

  // Add the continue shopping element and cart submit buttons.
  if (($type = variable_get('uc_continue_shopping_type', 'link')) != 'none') {
    // Render the continue shopping element into a variable.
    $cs_element = drupal_render($form['continue_shopping']);

    // Add the element with the appropriate markup based on the display type.
    if ($type == 'link') {
      $output .= '<div id="cart-form-buttons"><div id="continue-shopping-link">'
               . $cs_element .'</div>'. drupal_render($form) .'</div>';
    }
    elseif ($type == 'button') {
      $output .= '<div id="cart-form-buttons"><div id="update-checkout-buttons">'
               . drupal_render($form) .'</div><div id="continue-shopping-button">'
               .$cs_element.'</div></div>';
    }
  }
  else {
    $output .= '<div id="cart-form-buttons">'. drupal_render($form) .'</div>';
  }

  return $output;
}

 

in my smart_order_watch.module

function smart_order_watch_form_alter($form, &$form_state){

  switch ($form['form_id']['#value']){
    case'uc_cart_view_form':
    drupal_add_css(drupal_get_path('module', 'smart_order_watch') . '/smart_order_watch.css');

    $form['smart_order_save'] = array(
    '#type' => 'submit',
    '#value' => t('Save Order'),
    '#prefix'=>'<div id="continue-shopping-button" ',
    '#suffix'=>'</div >',
      );
 
    $form['#submit'][]='smart_order_watch_save_submit';
    break;
    }
}