Sorting Index alphabetically

Hi All,

How do I sort index alphabetically using xsl.

I have xml file like:

<Keyword>abc</keyword>
<Keyword>abcd</keyword>
<Keyword>abcde</keyword>
<Keyword>abcef</keyword>
<Keyword>bcdes</keyword>
<Keyword>Acdex</keyword>
<Keyword>Bcdes</keyword>
<Keyword>ccdes</keyword>
<Keyword>Ccdes</keyword>

I have to sort this as 

<h2>A</h2>
Acdes
Acdex
abc
abcd

<h2>B</h2>
Bcdes
Bcdes

Thanks,
Shailesh