private DefaultMutableTreeNode create_tree_node(Integer in_index){
		DefaultMutableTreeNode return_result = null;
		if(cur_level < tree_level){
			return_result = new DefaultMutableTreeNode(cur_level.toString() + in_index.toString());
			cur_level++;
			for(Integer i = 0; i < tree_width; i++){
				DefaultMutableTreeNode cur_node = create_tree_node(i);
				if(cur_node != null){
					return_result.add(cur_node);
				}
			}
			cur_level--;
		}
		return return_result;
	}