code: Object processAVT_QNAME(
            StylesheetHandler handler, String uri, String name, String rawName, String value, ElemTemplateElement owner)
              throws org.xml.sax.SAXException
    {
  
         AVT avt = null;
         try
         {
            avt = new AVT(handler, uri, name, rawName, value, owner);
      
            // If an AVT wasn't used, validate the value
            if (avt.isSimple())
            {
               int indexOfNSSep = value.indexOf(':');
  
               if (indexOfNSSep >= 0) 
               {   
                    String prefix = value.substring(0, indexOfNSSep);
                    if (!XML11Char.isXML11ValidNCName(prefix))
                    {
                       handleError(handler,XSLTErrorResources.INVALID_QNAME,new Object[]{name,value },null);
                       return null;
                    }
               }
                   
               String localName =  (indexOfNSSep < 0)
                   ? value : value.substring(indexOfNSSep + 1); 
               
               if ((localName == null) || (localName.length() == 0) ||
                   (!XML11Char.isXML11ValidNCName(localName)))
               {    
                       handleError(handler,XSLTErrorResources.INVALID_QNAME,new Object[]{name,value },null );
                       return null;
               }
            }  
          }
          catch (TransformerException te)
          {
             // thrown by AVT constructor
            throw new org.xml.sax.SAXException(te);
          } 
      
      return avt;
   }
docs: Process an attribute string of type T_QNAME into a QName value.
  
  @param handler non-null reference to current StylesheetHandler that is constructing the Templates.
  @param uri The Namespace URI, or an empty string.
  @param name The local name (without prefix), or empty string if not namespace processing.
  @param rawName The qualified name (with prefix).
  @param value A string that represents a potentially prefix qualified name.
  @param owner
  
  @return An AVT is returned.
  
  @throws org.xml.sax.SAXException if the string contains a prefix that can not be
  resolved, or the string contains syntax that is invalid for a qualified name.