AaronEldreth@cs.com wrote:

> The DTD would simply tell the browser how to interpret the If...then, 
> else, case and other handlers. XML or at least XHTML would be 
> streatched from a SGML based language, to a universal programming 
> language capable of doing anything.

  XHTML is not and should not be a programming language.  XHTML is 
called "Extensible HyperText Markup Language", NOT "Extensible HyperText 
Multipurpose Language", and, therfore, it is designed for marking up 
structure in documents only, and that's how it should stay.  Scripting 
XML documents is the domain of the Document Object Model [DOM] and the 
scripting language standards, like ECMAScript [ECMA-262].

[DOM] http://www.w3.org/DOM/ 
[ECMA-262] 
http://www.ecma-international.org/publications/standards/Ecma-262.htm 

CYA
...Lachy