XML development

Hi All

I am working with an SMS company that supplies a Base64 encoded image  
as part of an XML form submitted to my app.

If I am off track please point me in the right direction.

I am having it sent to a Direct Action but I am not sure what type of  
data type I should have...
It is being sent so - Standard XML document posted as a form in a  
single field called XmlMsg

I need to process it so this is what I am doing:

     public WOActionResults MMSAction(){

     String data = (String)this.request().formValueForKey("XmlMsg");
    org.jdom.input.SAXBuilder builder = new org.jdom.input.SAXBuilder 
(false);
   Document responseDoc = builder.build(data);
     Element response = responseDoc.getRootElement();
     Element rootElement = response.getChild("bspostevent");
    List xmlList = rootElement.getChildren("field");

But I think this is wrong as I get a file not found error on the   
builder.build(data); part!

This is an excerpt from the XML DTD:

<!--  bspostevent is an XML language - Typical usage:  <?xml  
version="1.0"?>  <bspostevent>    <field name="MobileNumber"  
type="string">+4477111222333</field>    <field name="Text"  
type="string">An SMS message body being handled</field>  </ 
bspostevent>-->

Can anyone help to give me some direction as the the correct syntax  
to be able to work with the elements...


Gino