void insert_account(FILE *fp, int accountnum)//新建账户
{
    BANKACCOUNT newaccount;
    newaccount.account = accountnum;
    int subkey;

    printf("请输入账号信息\n");
    printf(">>您的账号为:");
    printf("%d\n", accountnum);
    printf(">>请您输入密码:");
    scanf("%d",&(newaccount.key));
    system("cls");
    printf("请您再次输入刚才的密码：\n");
    do{
        scanf("%d", &subkey);
        getchar();
        if (subkey == newaccount.key)
            break;
        else
            printf("两次的密码不一样！\n请再次输入第一次的密码或输入0退出注册\n");
    }while (subkey !=  0);
    if (subkey != 0)
    {
        printf("密码设置成功！\n 请您完善个人信息\n");
        printf(">>姓名:");
        scanf("%s",newaccount.name);
        printf(">>请您输入初始余额:");
        scanf("%f",&(newaccount.balance));
        fseek(fp,0L,SEEK_END);
        fprintf(fp,"%d %d %s %.2f\n",newaccount.account,newaccount.key,newaccount.name,newaccount.balance);
        printf("账户创建成功！\n");
    }
    else
        printf("创建失败！");
}