I am an utter newbie to SRU and would be very grateful for your help. 

I am trying to implement an application in which the user 

(a) first scans an ISBN from a book, then 

(b) does a lookup via SRU to get information from the Library of Congress (and thereby avoid manual entry).

I am using (for example)

http://z3950.loc.gov:7090/voyager?version=1.1&operation=searchRetrieve&query=isbn=9781449313944

and I am getting back:

numberOfRecords: 0

diagnostic: message: Unsupported index

detail: isbn

However, if I get the Explain record, it says

<index id=“7”>

<title>isbn</title>

<map><name set=“bath”>isbn</name></map>

</index>

So I would have thought that what I attempted to do was legal.

[1] What am I missing here?

[2] How can I do an ISBN lookup?

Thank you for your help.

Cheers,

Rick Aurbach

Aurbach & Associates, Inc.