Number Swap

#include <iostream>
using namespace std;

void swap(int &x, int &y)
{
    int z;
    z = x;
    x = y;
    y = z;
}

int main()
{
    int n1, n2;
    cout << "Enter the first number: ";
    cin >> n1;
    cout << "\nEnter the second number: ";
    cin >> n2;
    system("cls");
    cout << "Preswap:\n";
    cout << "\n      First Number - " << n1 << endl;
    cout << "\n      Second Number - " << n2 << endl;
    swap(n1, n2);
    cout << "\nPostswap:\n";
    cout << "\n      First Number - " << n1 << endl;
    cout << "\n      Second Number - " << n2 << endl;
    cout << "\n";
    system("pause");
    return(0);
}