protected void nodeID(StreamTokenizer tk) throws Exception{
    
    if(tk.ttype=='"' || tk.ttype==tk.TT_WORD || (tk.ttype>='a' && tk.ttype<='z')
    || (tk.ttype>='A' && tk.ttype<='Z')) {
      if(m_nodes!=null && !(m_nodes.contains( new GraphNode(tk.sval, null))) ) {
        m_nodes.addElement( new GraphNode(tk.sval, tk.sval) );
        //System.out.println("Added node >"+tk.sval+"<");
      }
    }
    else
    { throw new Exception(); }
    
    //tk.nextToken();
  }