// JScript File for the cart operations
var gCartId; 
var gHMAC; 

function AddToCart(strASIN) { 
   // If no cart exists, then create a cart.        
   if (!IsGoodCart()) {
      // Create a NEW cart      
      GetData(3, "cart", 'Operation=CartCreate&Item.1.ASIN=' + strASIN + '&Item.1.Quantity=1&MergeCart=True');
   } else {
      // reuse the EXISTING cart      
      GetData(4, "cart", 'Operation=CartAdd&Item.1.ASIN=' + strASIN + '&Item.1.Quantity=1&MergeCart=True&CartId=' + gCartId + '&HMAC=' + gHMAC);
   }
}

function IsGoodCart (){ 
    // Does a cart cookie exist?   
    if  ((gCartId !="") & (gCartId !=null) & (gHMAC !="") & (gHMAC !=null)){
        // If so the cart is good. 
        return true;
    }
    return false;
}

function EmptyCart(){ 
    // Clear the cart cookies 
    EraseCookie('myCartId');
    EraseCookie('myHMAC');
    gHMAC=''; gCartId=''; 
    LoadCart();
}

function LoadCart(){ 
    // Helper function to load a cart
    gCartId = ReadCookie('myCartId');
    gHMAC = ReadCookie('myHMAC');
    
    if (IsGoodCart()) { 
        // a cart exists so load it...    
        GetData(4, "cart", 'Operation=CartGet&CartId=' + gCartId + '&HMAC=' + gHMAC);
    } else {
        document.getElementById('cart').innerHTML = 'No cart exists right now';
    }
}

function RemoveFromCart(strCartItemId){
    // If the cart exists...
    if (IsGoodCart()) {        
        // Remove the item
        GetData(4, "cart", 'Operation=CartModify&CartId=' + gCartId + '&HMAC=' + gHMAC + '&Item.1.CartItemId=' + strCartItemId + '&Item.1.Quantity=0');
    }     
}