Next Greater Node

public Node getNextGreater(Node n)
        {
            Node t = null;
            Node p = root;
            t = root;
            Node gp = null;
            while (t != null && !n.Equals(t))
            {
                gp = p;
                p = t;
                if (n.CompareTo(t) < 0)
                {
                    t = t.Left;

                }
                else
                {
                    t = t.Right;
                }

            }
            if (n.Data == this.getMax()) return null;
            if (t.Right == null && t.Equals(p.Right)) return gp;
            if (t.Right == null && t.Equals(p.Left)) return p;
            if (t.Right.Left == null && t.Right.Right == null) return t.Right;
            if (t.Right.Left != null) return t.Right.Left;
            return null;
        }