Amazon Product API: ItemLookup with Multiple ASINs

Question

So, I have a few problems figuring out why I am getting a specific error. [NOTE: I masked the AccessKey and Signature parameters]

The URL below returns valid xml for ONE product.

http://ecs.amazonaws.com/onca/xml?AWSAccessKeyId=[myAccessKey]&IdType=ASIN&ItemId=B002UD52WQ&Operation=ItemLookup&ResponseGroup=Medium&Service=AWSECommerceService&Timestamp=2010-07-27T23:17:57.000Z&Signature=[mySignature] 

However, when I use the url below to find multiple ASINs, comma separated ASINs, I get an error

 http://ecs.amazonaws.com/onca/xml?AWSAccessKeyId=[myAccessKey]&IdType=ASIN&ItemId=B002UD52WQ,B002C0CZEU&Operation=ItemLookup&ResponseGroup=Medium&Service=AWSECommerceService&Timestamp=2010-07-27T23:17:57.000Z&Signature=[mySignature] 

ERROR message:

The request signature we signed does not match your subscription provided. Verify your AWS Secret Access Key and Signature Method. Consult service documentation for details.

Does anyone know why this is happening? Thanks in advance.

DOCUMENTATION MAY BE FOUND HERE "To view more than one item at a time, separate item identifiers with commas."

Answer 1

Stupid, but you have to url commas. Hope this helps someone out there.