// in = url.openStream();
// }
if(in!=null){
Reader reader = new InputStreamReader(in);
DTDParser parser = new DTDParser(reader);
DTD dtd = parser.parse();
Object[] obj = dtd.getItems();
for(int i=0;i<obj.length;i++){
if(obj[i] instanceof DTDElement){
DTDElement element = (DTDElement)obj[i];
String name = element.getName();
comboDocumentRoot.add(name);