two stylesheets in an XML document?

[Dave <LI...@sheffield.ac.uk>]

Hi,
I am quite new to Xalan.
I am using the DefaultApplyXSL servlet and trying to include 
two <?xml-stylesheet ... > in an XML document, one for WML 
and the other for HTML, i.e.:

<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet  
href="http://localhost/project.nsf/workHtml.xsl?OpenPage" 
type="text/xsl"?>
<?xml-stylesheet  alternate="yes" 
href="http://localhost/project.nsf/workWml.xsl?OpenPage" 
type="text/xsl" media="up"?>
.....

But, this does not work. 
When I include only one <?xml-stylesheet ...>, it works well.
So, I think each stylesheet is all right.
Is this a stupid question?
Or are there any other ways to get around this?
I tried to access the mail list for answers but, it was impossible.

Waiting for guru's answers...

Thanks.

Dave