case key_down:
                     { if(y<17)
                         {
                           upbar(y);
                           y++;
                          }

                       break;
                      }
                     case key_up:
                     { if(y>7)
                         {
                           downbar(y);
                           y--;
                          }

                       break;
                      }


                   }

           }while(ky!=key_enter);
      textcolor(WHITE);
      switch(y)
        { case 9:
                {ch='%';
                  break;
                 }
           case 10:
                {clrscr();
                printf("now,begin to build stulist\n");

                 Build_List(Stu);

                 getch();
                  break;
                 }
           case 11:
                {clrscr();
                Print_List(Stu);
                 getch();
                  
                  break;
                 }
           case 12:
                {clrscr();
                printf("enter insert record:\n");
                Insert(Stu);
                 getch();
                  break;
                 }
           case 13:
                {clrscr();
                printf("enter correct number:");
           scanf("%s",num0);
           Correct(Stu,num0);

                 getch();
                  break;
                  }
           case 14:
                {clrscr();

                printf("enter 0 to increase sort,enter 1 to decrease sort:");
                 scanf("%d",  &label);
                 Sort(Stu,label);

                 getch();
                  break;
                  }
           case 15:
                {clrscr();
                printf("enter search number:");
                 scanf("%s",num0);
                 Search(Stu,num0);

                 getch();
                  break;
                  }
           case 16:
                {clrscr();
                Statistic(Stu);
                 getch();
                  break;
                  }
            case 17:
                {clrscr();
                printf("8\n");
                 getch();
                  break;
                  }

         }
       if(ch=='%')
        break;
      }while(1);

}
   }