elsif ($choice eq "add")			# add item to shopping cart
{
	add_item ($dbh, $cart_ref, param ("item_id"), param("quantity"), param("color"));
	$page .= format_cart_html ($cart_ref, 1);
}

##</code><code>##

sub get_product_table
{
my $sth = shift;
my @row;
my @nav_link;
my @color;


	
	while (my $ref = $sth->fetchrow_hashref ())
	{

	 my $serve_url = sprintf ("serve_image.cgi?item_id=%s;picture", escape ($ref->{item_id}));            	

@color = split (/,/, $ref->{color});

# generate a form allowing a quantity of the item to be added
# to the cart
push (@row, start_form(-method=>'POST', -action=>url()),
hidden( -name => "choice", -override => 1, 
-default => "add" ),
hidden( -name => "item_id", -override => 1,  -default => escapeHTML($ref->{item_id})),
        Tr ({-style=>"font-family: verdana; font-size: 10pt;"},
   td (img ({-src => $serve_url, -alt => escapeHTML($ref->{item_id})})), 
   td ({-width=>"80", -valign=>"top", -align => "center"}, escapeHTML( $ref->{item_id} )),
   td ({-width=>"190", -valign=>"top"}, escapeHTML( $ref->{description} ))),
   td (" "),
   Tr ({-style=>"font-family: verdana; font-size: 10pt;"}, 
   td ({-colspan => "3", -align => "right", -style=>"font-weight: 700; color:blue;"}, "Price:  \$", escapeHTML( sprintf( "%.2f", $ref->{price}))),
   Tr ({-style=>"font-family: verdana; font-size: 10pt;"}, 
   td ({-colspan => "3", -align => "right"}, "Colors:", popup_menu( -name => "color", -values => \@color))),
   Tr ({-style=>"font-family: verdana; font-size: 10pt;"}, 
   td ({-colspan => "3", -align => "right"}, "Quantity:", popup_menu( -name => "quantity", -values => ["1", "2", "3", "4", "5", "6", "7", "8", "9"])),
   td (image_button( -name => "Add Item", -src=>"../images/add.jpg", -border=>"0" )))),
   Tr ({-valign=>"top"},
   td ({-colspan=>"7", -width=>"100%"}, hr)),
end_form()
);

	}
	$sth->finish ();

	return undef unless @row;		# no items?

	return (table ({-border => 0, -align => "center", -style=>"font-family: verdana; font-size: 10pt;"}, @row));
                 
     
}

##</code><code>##

sub add_item
{
my ($dbh, $cart_ref, $item_id, $qty, $color) = @_;

	# If the item isn't already in the cart, look it up from the database
	# and store it in the cart as a new entry with a quantity of zero.
	if (!exists ($cart_ref->{$item_id}))
	{
		my $sth = $dbh->prepare ("SELECT * FROM catalog_pet
									WHERE item_id = ?");
		$sth->execute ($item_id);
		my $item_ref = $sth->fetchrow_hashref ();
		$sth->finish ();
		return if !defined ($item_ref);	# this shouldn't happen...
		$cart_ref->{$item_id} = {};	# create new entry, indexed by item ID
		$cart_ref->{$item_id}->{description} = $item_ref->{description};
		$cart_ref->{$item_id}->{price} = $item_ref->{price};
		$cart_ref->{$item_id}->{qty} = 1;
	}
	$cart_ref->{$item_id}->{qty} = $qty;	
                $cart_ref->{$item_id}->{color} = $color;	
}

##</code><code>##

sub format_cart_html
{
my ($cart_ref, $show_links) = @_;
my $total_price = 0;
my @row;

	if (!keys (%{$cart_ref}))
	{
		return (p ("Shopping cart is empty."));
	}
                $page .= h3 ({-align=>"center", -style=>"font-family: verdana; font-size: 16pt; color: blue;"}, ("Shopping Cart"));
	push (@row, Tr ({-align => "CENTER",  -valign=>"TOP",  -BGCOLOR=>"silver",  -style=>"font-family: verdana; font-size: 10pt;"},
                                 
                        
                        th ({-width=>"50"},("Item")),
				th ({-width=>"50"},("Qty")),
                                                                 th ({-width=>"90"},("Color")),
				th ({-width=>"190"},("Description")),
				th ({-width=>"94"},("Unit Price")),
				th ({-width=>"94"},("Price"))
                                  
			));
	foreach my $item_id (sort (keys (%{$cart_ref})))
	{
		my $item_ref = $cart_ref->{$item_id};
		my $total_item_price = $item_ref->{qty} * $item_ref->{price};
		$total_price += $total_item_price;
		# generate a link allowing the item to be deleted from the cart
		my $url = sprintf ("%s?choice=delete;item_id=%s",
							url (), escape ($item_id));
                                push (@row, start_form(-method=>'GET', -action=>url()),
hidden( -name => "choice", -override => 1,  -default => "update" ),
hidden( -name => "item_id", -override => 1, -default => escapeHTML( $item_id )),

                               Tr ({-valign=>"center", -style=>"font-family: verdana; font-size: 10pt;"},
                               
                               td ({-align => "center"},(escapeHTML ($item_id))),
                               td ({-align => "center"},( textfield( -name => "quantity", -size => "1", -override => 1, -value => $item_ref->{qty}))),
                                td (escapeHTML ($item_ref->{color})),
					td (escapeHTML ($item_ref->{description})),
					td ({-align => "right"},
						escapeHTML (sprintf ("%.2f", $item_ref->{price}))),
					td ({-align => "right"},
						escapeHTML (sprintf ("%.2f", $total_item_price))),
                             td (a ({-href => $url}, img ({-src => "../images/delete1.jpg",  -border => "0"}))),
                             td (image_button( -name => "update", -src=>"../images/update1.jpg", -border=>"0" )),
                                 end_form()

				));
        	}
	push (@row, Tr ({-align => "CENTER",  -valign=>"center", -style=>"font-family: verdana; font-size: 10pt;"},
				td ({-colspan => "2"}, ""),
				td ({-colspan => "3", -align=>"right", -style=>"font-weight: 700;"}, "Total"),
				td ({-align => "right", -style=>"font-weight: 700;"},
					escapeHTML (sprintf ("%.2f", $total_price)))

			));
        	return (table ({-align => "CENTER", -border => 0}, @row));
}