[xsl] Unique attribute values

["Sean Tiley" <sean.tiley@xxxxxxxxx>]

Hi there,
I have the following structure in an XML file

<root>
 <file name="c:\test.java">
  <error line="4" message="Message1" severity="2"/>
  <error line="67" message="Message2" severity="4"/>
 </file>
  <file name="c:\code.java">
  <error line="2" message="Message1" severity="2"/>
  <error line="54" message="Message2" severity="4"/>
  <error line="122" message="Message1" severity="2"/>
  <error line="124" message="Message2" severity="4"/>
 </file>
</root>

What I want to do is the following.
I want a list of the unique values for the message attribute
I then want to output attribute value and the number of times it
appears in the file.

I can successfully get the count for an attribute value by using
<xsl:value-of select="count(/root/file/error[@message='Message1'])"/>
but I am hardcoding the 'Message1" which is clearly not optimal

Any suggestions are greatly appreciated


Thanks
Sean