var in_cart_background_color = "#fafd12";
var added_items = new Array();

var product_id, product_div_id, cart_button_id;


function add_catalog_item(_product_id, _product_div_id, _cart_button_id)
{
    product_id = _product_id;
    product_div_id = _product_div_id;
    cart_button_id = _cart_button_id;

    if (already_in_cart(product_id))
    {
	return;
    }

    // add the product to the cart
    shopping_cart_add_item(product_id, add_item_callback);
}


function item_added_ok()
{
    // put the item in the items array
    added_items.push(product_id);

    // change the catalog item text background
    var product_div = document.getElementById(product_div_id);
    product_div.style.backgroundColor = in_cart_background_color;
    
    // change the button text and onClick function 
    var cart_button = document.getElementById(cart_button_id);
    cart_button.value = "in cart";
}




function already_in_cart(product_id)
{
    for (i = 0; i < added_items.length; i++)
    {
	if (added_items[i] == product_id)
	{
	    alert("The item is already in your cart.");
	    return true;
	}
    }

    return false;
}