Double Linked List Problem

void hapusTengah()
{
    int cari,depan;
    hapus = head;   // letakan hapus pada head
    cout<<"NIM yang akan dihapus : ";
    cin>>cari;
    if(isEmpty()==0)
    {
        while (hapus->next != NULL && hapus->NIM != cari)
            hapus = hapus->next;

        if (hapus->NIM == cari)
        {
            bantu2 = hapus->next;
            bantu  = hapus->prev;

            if (head != hapus)
                bantu->next = bantu2;
            else
                head = bantu2;

            if (tail != hapus)
                bantu2->prev = bantu;
            else
                tail = bantu;

            delete hapus;
        }
    }
    else
    {
        cout<<"Tabel masih kosong"<<endl;
        int nomor=0;
    }
}