public TNode createTree (ASCIIDataFile in) {
    	String c;
    	TNode last_right = null;
    	TNode tree = new TNode(null, null, in.readLine());
    	while(in.isEOF()==false) {
    		c = in.readLine();
    		tree = insert(c, tree);
    	}
    	Rthread(tree);
  //			System.out.println("-----------------------------------------");
   // 	Lthread(tree);

		return tree;
    }
    public TNode insert ( String s, TNode t) {
    	if (s != null) {
    		if (t == null) {
    			t = new TNode(null, null, s);
    		}
    		else if (s.compareTo(t.content) < 0 && t.ltag==false) {
    			t.left = insert(s, t.left);
    		}
    		else if (s.compareTo(t.content) > 0 && t.rtag==false) {
    			t.right = insert(s, t.right);
    		}
    		else {
    		};
    	}
    	return t;
    }