主题：关联表的自动编号问题

定单表与生产表能过定单号码相关联,  如: GH-0901001

如何设置生产号的自动编号,  具体生产号是这样产生的

如定单号码为: GH-0901001  则生产号为: 001001
                                                        001002
                                                        001003
                                                        001004
                                                         .........
如定单号码为: GH-0901121   则生产号为:  121001
                                                          121002
                                                         121003
                                                         121004
                                                         .........

请问DataRowAdding的代码应该如何写啊,谢谢!