> My assumption is that you are using .NET and this is custom 
> URIResolver
> that you are referring to?

.NET chose to call its version of the URIResolver an XmlResolver, so I
suspect the question relates to Java JAXP rather than .NET.

> Either way, it doesn't matter because the
> easiest way to solve your problem is to wrap the document() function
> within a boolean() function which will evaluate to true if the file
> exists and false if it does not.

That only works if the XSLT processor chooses to take the (optional)
recovery action from the error that occurs when a document can't be found.
So this solution isn't portable.

Michael Kay