[xsl] Extract attribute from markup returned by extension function

[John <john-xsl-list@xxxxxxxx>]

Hello,

An XSL extension function returns markup such as <img 
src="/path/to/image.jpg" border="0" alt="" />.  I can't guarantee the / 
will be provided so it may not be XML markup.  I am only interested in 
the value of the src attribute.  I am hoping the code can be as flexible 
as possible (attributes could appear in any order, and it would be nice 
to support single quotes (') in addition to double-quotes (") in the 
data.  I was thinking of starting with the string functions, but I am 
curious if there might be a better way.

TIA,

   -John