WordPress Ultra Simple Paypal Shopping Cart with custom fields

Hi

how can i get PRODUCT-NAME and PRODUCT-PRICE in custom fields

the php code with this plugin like this <?php echo print_wp_cart_button_for_product('PRODUCT-NAME', PRODUCT-PRICE); ?>

I made 2 custom fields in my wordpress dashboard and i maked the code in page like this

<?php echo print_wp_cart_button_for_product(array(
										 get_post_meta($post->ID,'PRODUCT-NAME',true),
										 get_post_meta($post->ID,'PRODUCT-PRICE',true),
								)); ?>

but it did’t work so
how can i handle the with custom fields ??

http://wordpress.org/extend/plugins/wp-ultra-simple-paypal-shopping-cart/