XPath incorrect query path

[Colin]

I have been trying for a long time to extract a string from the following xml with no luckhttp://chris.photobooks.com/xml/default.htm?state=8TI am trying to get the ASIN number of a book and I have tried \[code\]$xpath->query('//MarketplaceASIN/ASIN')->item(0)->nodeValue;\[/code\]and \[code\]$xpath->query('/GetMatchingProductResponse/GetMatchingProductResult[1]/Product/Identifiers/MarketplaceASIN/ASIN')->item(0)->nodeValue;\[/code\]but neither seem to work, what am I doing wrong here?