下面的输入N可以退出循环，但是输入任意都能继续执行循环，怎么才能做到输入Y才能继续循环，输入其他都不能？

int Input(SqList &L,int n){
    int i=0;
    char j,a[10];
    while(j!='n'&&j!='N'){   
        printf("\t编号:");   
        scanf("\t%d",&L.elem[n+i].num);   
        printf("\t姓名:");  
        scanf("\t%s",&L.elem[n+i].name);   
        printf("\t年龄:");   
        scanf("\t%s",&L.elem[n+i].age);   
        printf("\t电话号码:");   
        scanf("\t%s",&L.elem[n+i].phone);   
        printf("\t通讯住址:");   
        scanf("\t%s",&L.elem[n+i].adds);   
        printf("\t电子邮箱:");
        scanf("\t%s",&L.elem[n+i].email);   
        gets(a);
        printf("\n\t是否继续添加 (Y/N)");
        scanf("\t%c",&j);
        i++;  
    }
    return(n+i);
}

额，就是不知道怎么检验yn