paypal says cart is empty

Hi,
I am using my paypal sandbox to process orders. When I click on Place your order (checkout). I get the message from paypal: Your cart is empty. I checked the script, and cannot see why it would see an empty cart. Could you please check it out?
Thank you,
K
On this confirm I did not change the line directing the confirm to my sand box, I did change it and I still get the same error message that the cart is empty.
line that I changed that is not in the script I sent:
<form name="checkout_PP_LI_Hid" action="https://www.sandbox.paypal.com/cgi-bin/webscr"
method="post"
The account number is my sand box account

please post a link where I can see the problem to investigate the cause.

The page looks ok to me, so long as you are matching up the account with the correct URL it seems that this should work. Do you see the items on the page when you get to the confirm page? If so and you submit the form it should send the cart contents to PayPal directly. Do you have a link where we can check on this?

Hi Eric,
I figured out why, I did not have the following:
<input type="hidden" name="item_name_<?php echo $winkee_Index+1; ?>" id="item_name_<?php echo $winkee_Index+1; ?>" value="<?php echo $winkee->DisplayInfo("ID") ?>" />

instead I had:
<input type="hidden" name="item_name_<?php echo $winkee_Index+1; ?>" id="item_name_<?php echo $winkee_Index+1; ?>" value="<?php echo $winkee->DisplayInfo("Name") ?>" />

I know that the hidden fields are sent to paypal. I have some questions about them:
1. If I put anything else here but ID, the order is not seen by paypal. So this is where I bound the prodid? Also where does the item_name come from?
<input type="hidden" name="item_name_<?php echo $winkee_Index+1; ?>" id="item_name_<?php echo $winkee_Index+1; ?>" value="<?php echo $winkee->DisplayInfo("ID") ?>" />
In this one I put the SKU Number, Where did the item_number come from?
<input type="hidden" name="item_number_<?php echo $winkee_Index+1; ?>" id="item_number_<?php echo $winkee_Index+1; ?>" value="<?php echo $winkee->DisplayInfo("SKU") ?>" />
In these fields I can add more, can I change "on0_ and if so if I wanted to change it to size, how would I do that
<input type="hidden" name="on0_<?php echo $winkee_Index+1; ?>" id="on0_<?php echo $winkee_Index+1; ?>" value="" />
<input type="hidden" name="os0_<?php echo $winkee_Index+1; ?>" id="os0_<?php echo $winkee_Index+1; ?>" value="" />
<input type="hidden" name="on1_<?php echo $winkee_Index+1; ?>" id="on1_<?php echo $winkee_Index+1; ?>" value="" />
<input type="hidden" name="os1_<?php echo $winkee_Index+1; ?>" id="os1_<?php echo $winkee_Index+1; ?>" value="" />

When I got through to PP, I noticed that the headings were limited, only ID, description, price and total. Is this because of the way I have my fields, or is it a paypal issue?
Thank you,
K

The name of the item that you send to PayPal is contained in the name element. The id value that you are using is the itemID that is set in the add to cart server behavior. The SKU is just another column in your cart, using it for the item number is appropriate. If it is working for you like this then it seems that you have it setup correctly.

For the options you would use the on0 and os0 for the first option name and option selection (value), then on1 and os1 for the second option name and value. Each item can have multiple options and values for it. So if you would like to show an item as having a particular size it might look like this:

<input type="hidden" name="on0_<?php echo $winkee_Index+1; ?>" id="on0_<?php echo $winkee_Index+1; ?>" value="Size" />

<input type="hidden" name="os0_<?php echo $winkee_Index+1; ?>" id="os0_<?php echo $winkee_Index+1; ?>" value="<your size column from the cart>" />

You would bind the size column from your cart to the os0 value.