{
Hashtable<String, DTDElement> roots = new Hashtable<String, DTDElement>();
Enumeration<?> e = dtd.elements.elements();
while(e.hasMoreElements())
{
DTDElement element = (DTDElement)e.nextElement();
roots.put(element.name, element);
}
e = dtd.elements.elements();
while(e.hasMoreElements())
{
DTDElement element = (DTDElement)e.nextElement();
if(!(element.content instanceof DTDContainer))
{
continue;
}