Here String error,

Here my C++ code, when I enter string name then its create error and mix the string. kindly help me out. **************** code C++ **************

enter code here   
 #include <iostream>
using namespace std;
#include <conio.h>
#include <stdio.h>
#include<string>
#include<fstream>
void main()
{
    char str[100];
    ofstream out("c:\\city.txt");
    ifstream in("c:\\city.txt");
    for (int i = 0; i < 5; i++)
    {
        cout << "Enter a string:";
        cin>>str;
        out << str << "\n";
    }
    out.close();
    cout << "The list of strings is as follows:" << endl;
    while (!in.eof())
    {
        in.getline(str, 100);
        cout <<str<<endl;
    }
    in.close();
    system("pause");
}