public static Enumeration listRoots() {

		if (listenRoots == null)
			initRoots();

		if (listenRoots != null) {

			Vector v = new Vector();

			for (int i = 0; i < listenRoots.length; i++) {
				File rootDir = new File(listenRoots[i]);
				if ((rootDir != null) && (rootDir.exists())) {
					v.addElement(listenRoots[i]);
				}
			}

			String[] roots = new String[v.size()];

			for (int i = 0; i < roots.length; i++) {
				String root = (String) v.elementAt(i);
				root = root.substring(0, root.length());
				roots[i] = root;
			}
			
			return new FileRootEnumeration(roots);
		}

		return new FileRootEnumeration(null);
	}