Need simple coding help for Shopping Cart in Header

[georgiepants]

v1.3.8a
This is what I have so far,



What I would like is to have the word "item(s)" be either "item" or "items" depending on the cart contents being 1 item or multiple items.

I need coding help to add "echo" and "if" commands to the tpl_header.php to call on the following new defines that I've added to .../custom/english.php

..CUSTOM/english.php

// Shopping Cart Totals in Header display
// only for where one item in cart: 
  define('ONE_ITEM_IN_CART', 'item');
// only for where multiple items in cart:
  define('MULTIPLE_ITEMS_IN_CART', 'items'); 

...templates/CUSTOM/common/tpl_header.php

<!--bof Shopping Cart Totals in Header Add-on-->
    <!--NOTE: this add-on was modified to correct an error in cart totals $$ (check forum post subsciptions for code details)-->
    <!--"//"Comment or Uncomment to use-->
  
      <span class="style1">
        <li><a href="<?php echo zen_href_link(FILENAME_SHOPPING_CART, '', 'NONSSL'); ?>">
            My Cart: <?php echo ($_SESSION['cart']->count_contents()); ?> item(s)&nbsp;
          </a>
          <?php $header_cart = $currencies->format($_SESSION['cart']->show_total());  echo $header_cart;?>
        </li>
      </span>
    <!--eof Shopping Cart Totals in Header Add-on-->

    <!--"//" comment or uncomment to hide/use this original code-->
<?php if ($_SESSION['cart']->count_contents() != 0) { ?>
    <!--keep tag info commented out if php is commented out otherwise it will cause an invisible link to the index next to the LogIn link in nav
    <li><a href="<?php //echo zen_href_link(FILENAME_SHOPPING_CART, '', 'NONSSL'); ?>"><?php //echo HEADER_TITLE_CART_CONTENTS; ?></a></li>-->
  <li><a href="<?php echo zen_href_link(FILENAME_CHECKOUT_SHIPPING, '', 'SSL'); ?>"><?php echo HEADER_TITLE_CHECKOUT; ?></a></li>

<?php }?>

I'm not a programmer but I kind of get the idea of what I need, just not sure how to execute the code.

Any help is greatly appreciated!