How do you access an element by its attribute value using XSL transforms and XML?

[lloyd1981]

Im trying to transform an XML document into XHTML using XSL transformation and was wondering how i can choose an XML element given the value of its attribute. e.g.\[code\]<image size="small">http:example.small.jpg</image><image size="medium">http:example.medium.jpg</image><image size="large">http:example.largw.jpg</image>\[/code\]I only want to access the value "http:example.medium.jpg" from the image tag where size="medium".Any help is greatly appreciated.Ally