Still confused...

#include "stdafx.h"
#include <iostream>
#include <string>
using namespace std;

void main()
{
    double temp = 0.0;
    string = x;

    cout << "Please enter the temperature: ";
    cin >> temp;
    cout << endl;

    cout << "Please enter if the temperature is in fahrenheit or celsius: ";
    cin >> x;
    cout << endl;

    if (x = fahrenheit)
    {
        temp = temp-32/1.8;
        cout << "The temperature in celsius is: " << temp << endl;
    }
    else
    {
        temp = temp*1.8+32;
        cout << "The temperature in fahrenheit is: " << temp << endl;
    }


    cout << endl << endl;
    system("pause");
}