XML for dynamic data

Hi,
i am new to XML and need help from you:
i have created a HTML file that does the following: using select and option tags; a list of names and ages are provided. every name has a predefined age. the user has to select a name and an age and click on the submit button. if he selects the correct match, a congratulatory message is displayed and if not,an error message is displayed.the matching is done on the server side using a servlet.
what i need to accomplish is that: when the submit button is clicked by the user, an XML file defining the user selection is to be created. this XML is sent to the server which interprets the inputs and using servlets produces the output.
the above problem may seem too trivial to use XML,servlets etc. but the fact is that i have to implement a similar functionality(much more complex) and the main reason for me to post this question is to know how to define XML for dynamic data ie data which the user can change anytime, as shown above. this XML file is used by a servlet to perform processing. i am more interested in how to define XML for dynamic data.
since i am new to XML, i am really finding it difficult to implement such a functionality
waiting to get a reply at the earliest.
thanks in advance.

XML is perfectly suited to dynamic data, there's no need to define a "special" type. What you'll need to do is define an XML schema or DTD, then you'll write your XML file according to this, eg; <name>someName</name>
<age>23</age>
Java has inbuilt libraries for navigating through the DOM of an XML (the way the XML is stored in memory), parsing and writing XML according to your schema. You'll find tutorials for all these things all over the place, start with google.

HTH,
W