at the top of your page add the following lines, (browse for the exact file name to avoid typos)...
where NAME_OF_CART is the name of your ecart instance
<?php
require_once("WA_eCart/NAME_OF_CART_PHP.php");
?>
<?php
$NAME_OF_CART->GetContent();
?>
then in your body add
Cart Total: <?php echo WA_eCart_DisplayMoney($NAME_OF_CART, $NAME_OF_CART->GrandTotal()); ?>