code: public Object getVariableValue(String namespaceURI, String prefix, String localName) throws UnresolvableException {
          if (this.request.hasAttribute(localName)) {
              return String.valueOf(this.request.getAttribute(localName));
          }
          
          return null;
      }
docs: /* (non-Javadoc)
  @see org.jaxen.VariableContext#getVariableValue(java.lang.String, java.lang.String, java.lang.String)