Generate indexes automatically from xml file using xsl

Hi All,

I have to generate index file from xml file as input using xsl.
In xml file there is an element 
<Keywords>
<Keyword>Test</keyword>
<Keyword>Test1</keyword>
<Keyword>Test2</keyword>
</keywords>

How should I do this using xsl, is there any references for the same.


Thanks,
Shailesh