[c++] C++ Cout & Cin & System "Ambiguous"

I was just programming in c++, when all of a sudden all the "cout"s and "cin"s were errors and "Ambiguous". Including System.

I don't know why this happened. Everything was fine, I was coding the same program for about 2 hours, when it just... happened.

EDIT

I can still run the program without errors, but they show as errors on the text, the red scribbly line. What happened?

I'm using the Visual Studio 2013 IDE, whatever it comes with.

#include <iostream>
#include <ctime>
#include <string>
#include <Windows.h>
#include <cstdlib>
#include <stdlib.h>

using namespace std;

int main()
{

struct Gun
{
    string name;
    int damage;
    int cost;
    bool purchased;
    bool equipped;

} M4A1, FAMAS;

//WEAPONS INFO
M4A1.cost = 50;
M4A1.damage = 5;
M4A1.purchased = false;
M4A1.equipped = false;

FAMAS.cost = 300;
FAMAS.damage = 10;
FAMAS.purchased = false;
FAMAS.equipped = false;
//WEAPONS INFO

//-----PLAYER(BEGIN)-----

struct Player
{
    int health;
    string name;
    int money;
    int energy;

    string l_a;
    string r_a;
    string l_l;
    string r_l;

    string rank;

} Player;

//GAME PLAYER BEGIN

Player.l_a = "Normal";
Player.r_a = "Normal";
Player.l_l = "Normal";
Player.r_l = "Normal";

Player.health = 100;
Player.money = 100;
Player.energy = 100;

string plyrname;
string rank = "Private";

Player.name = plyrname;

//GAME PLAYER END

//-----PLAYER(END)-----

cout << "What is your name? ";
cin >> plyrname;

goto mmenu;


mmenu:

//-----MAIN MENU(BEGIN)-----
system("CLS");
if (Player.l_a == "Damaged")
{
    cout << "Your Left Arm is damaged! Sleep for a while to fix it!";
    Sleep(1600);
}
if (Player.r_a == "Damaged")
{
    cout << "Your Right Arm is damaged! Sleep for a while to fix it!";
    Sleep(1600);
}
if (Player.l_l == "Damaged")
{
    cout << "Your Left Leg is damaged! Sleep for a while to fix it!";
    Sleep(1600);
}
if (Player.r_l == "Damaged")
{
    cout << "Your Right Leg is damaged! Sleep for a while to fix it!";
    Sleep(1600);
}


if (Player.money >= 500 && Player.rank == "Private")
{
    system("CLS");
    cout << "You have been promoted to Private 2!";
    Player.rank = "Private 2";
    Sleep(1600);

}

if (Player.money >= 1000 && Player.rank == "Private 2")
{
    system("CLS");
    cout << "You have been promoted to Private First Class!";
    Player.rank = "Private First Class";
    Sleep(1600);
}


system("CLS");
cout << "Health: " << Player.health << ". Money: " << Player.money << " dollars." << "   Energy: " << Player.energy;
if (M4A1.equipped)
    cout << "\nGun: M4A1";
if (FAMAS.equipped)
    cout << "\nGun: FAMAS";

cout << "\n\nRank: " << Player.rank;
cout << "\n\n1) Go to Gunstore\n2) Sleep\n3) Fight\n\nAction: ";
int mmenuch1;
cin >> mmenuch1;

if (mmenuch1 == 1)
{
    goto gunstore;
}

if (mmenuch1 == 2)
{
    system("CLS");
    cout << "You sleep, restoring your energy.";
    Player.energy = 100;

    if (Player.l_a == "Damaged")
    {
        cout << "\n\nYour Left Arm was healed.";
        Player.l_a = "Normal";
    }
    if (Player.r_a == "Damaged")
    {
        cout << "\n\nYour Right Arm was healed.";
        Player.r_a = "Normal";
    }
    if (Player.l_l == "Damaged")
    {
        cout << "\n\nYour Left Leg was healed.";
        Player.l_l = "Normal";
    }
    if (Player.r_l == "Damaged")
    {
        cout << "Your Right Leg was healed.";
    }


    Sleep(1400);
    goto mmenu;
}

if (mmenuch1 == 3)
{
    system("CLS");
    goto fight;
}

//-----MAIN MENU(END)-----


fight:
srand(time(0));

system("CLS");

if (Player.r_a == "Damaged" || Player.r_l == "Damaged" || Player.l_a == "Damaged" || Player.l_l == "Damaged")
{
    cout << "You're injured, sleep to heal.";
    Sleep(1400);
    goto mmenu;
}

if (Player.energy < 40)
{
    cout << "You don't have enough energy to fight.";
    Sleep(1400);
    goto mmenu;
}

if (M4A1.equipped == false && FAMAS.equipped == false)
{
    cout << "You don't have a gun equipped.";
    Sleep(1400);
    goto gunstore;
}

if (M4A1.equipped == true && Player.energy > 40)
{

    int randnum1 = rand() % (M4A1.damage - 2 + 1) + 2;
    Player.money = Player.money + (randnum1 * 15);
    Player.energy = Player.energy - 40;

    int randnum3 = rand() % (10 - 1 + 1) + 1;
    if (randnum3 < 4)
    {

        int randnum4 = rand() % (13 - 1 + 1) + 1;

        if (randnum4 < 3)
        {
            Player.l_a = "Damaged";
        }
        if (randnum4 <= 6 && randnum4 >= 4)
        {
            Player.r_a = "Damaged";
        }
        if (randnum4 <= 9 && randnum4 >= 7)
        {
            Player.l_l = "Damaged";
        }
        if (randnum4 <= 13 && randnum4 >= 10)
        {
            Player.r_l = "Damaged";
        }



    }


    cout << "You fight, killing " << randnum1 << " enemies, making " << randnum1 * 15 << " dollars!";
    Sleep(1600);
    goto mmenu;





}




if (FAMAS.equipped == true && Player.energy > 40)
{
    int randnum2 = rand() % (FAMAS.damage - 4 + 1) + 4;
    Player.money = Player.money + (randnum2 * 15);
    Player.energy = Player.energy - 40;




    int randnum5 = rand() % (10 - 1 + 1) + 1;
    if (randnum5 < 4)
    {

        int randnum6 = rand() % (13 - 1 + 1) + 1;

        if (randnum6 < 3)
        {
            Player.l_a = "Damaged";
        }
        if (randnum6 <= 6 && randnum6 >= 4)
        {
            Player.r_a = "Damaged";
        }
        if (randnum6 <= 9 && randnum6 >= 7)
        {
            Player.l_l = "Damaged";
        }
        if (randnum6 <= 13 && randnum6 >= 10)
        {
            Player.r_l = "Damaged";
        }



    }



    cout << "You fight, killing " << randnum2 << " enemies, making " << randnum2 * 15 << " dollars!";
    Sleep(1600);
    goto mmenu;
}



//-----GUNSTORE(BEGIN)-----
gunstore:
system("CLS");
cout << "Welcome to the gunstore! You have " << Player.money << " dollars.";
cout << "\n\n1)M4A1 | Assault Rifle | $50\n2)FAMAS | Assault Rifle | $300\n\n3)Back\n\nAction: ";

int gschoice1;

cin >> gschoice1;

if (gschoice1 == 1)
{
    goto prchs_M4A1;
}
else if (gschoice1 == 2)
{
    goto prchs_FAMAS;
}
else if (gschoice1 == 3)
{
    goto mmenu;
}


prchs_M4A1:

system("CLS");

if (M4A1.purchased == true)
{
    cout << "You already purchased the M4A1. Would you like to equip it?\n\n1)Yes\n2)No\n\nAction: ";
    int gschoice6;
    cin >> gschoice6;

    if (gschoice6 == 1)
    {
        system("CLS");
        M4A1.equipped = true;
        FAMAS.equipped = false;
        goto mmenu;
    }
    else if (gschoice6 == 2)
    {
        goto gunstore;
    }


}


if (Player.money >= 0)
{
    system("CLS");
    cout << "Would you like to buy the M4A1?";
    cout << "\n\n1)Yes\n2)No\n\nAction: ";

    int gschoice2;
    cin >> gschoice2;

    if (gschoice2 == 1)
    {
        system("CLS");
        Player.money = Player.money - M4A1.cost;
        M4A1.purchased = true;
        cout << "You've purchased the M4A1. Would you like to equip it?\n\n1)Yes\n2)No\n\nAction: ";
        int gschoice3;
        cin >> gschoice3;



        if (gschoice3 == 1)
        {
            system("CLS");
            M4A1.equipped = true;
            FAMAS.equipped = false;

            cout << "You've equipped the M4A1";
            Sleep(1400);
            goto gunstore;
        }

        if (gschoice3 == 2)
        {
            system("CLS");
            M4A1.equipped = false;
            goto gunstore;
        }


    }

    if (gschoice2 == 2)
    {
        system("CLS");
        goto gunstore;
    }

}
else if (Player.money < 0)
{
    system("CLS");
    cout << "You don't have enough money.";
    Sleep(1400);
    goto gunstore;
}

prchs_FAMAS:

if (FAMAS.purchased == true)
{
    cout << "You already purchased the FAMAS. Would you like to equip it?\n\n1)Yes\n2)No\n\nAction: ";
    int gschoice7;
    cin >> gschoice7;

    if (gschoice7 == 1)
    {
        system("CLS");
        FAMAS.equipped = true;
        M4A1.equipped = false;
        goto mmenu;
    }
    else if (gschoice7 == 2)
    {
        goto gunstore;
    }
}



    if (Player.money >= 100)
    {
        system("CLS");
        cout << "Would you like to buy the FAMAS?";
        cout << "\n\n1)Yes\n2)No\n\nAction: ";

        int gschoice4;
        cin >> gschoice4;

        if (gschoice4 == 1)
        {
            system("CLS");
            Player.money = Player.money - FAMAS.cost;
            FAMAS.purchased = true;
            cout << "You've purchased the FAMAS. Would you like to equip it?\n\n1)Yes\n2)No\n\nAction: ";
            int gschoice5;
            cin >> gschoice5;

            if (gschoice5 == 1)
            {
                system("CLS");
                FAMAS.equipped = true;
                M4A1.equipped = false;
                cout << "You've equipped the FAMAS";
                Sleep(1400);
                goto gunstore;
            }

            if (gschoice5 == 2)
            {
                system("CLS");
                FAMAS.equipped = false;
                goto gunstore;
            }


        }

        if (gschoice4 == 2)
        {
            system("CLS");
            goto gunstore;
        }

    }
    else if (Player.money < 100)
    {
        system("CLS");
        cout << "You don't have enough money.";
        Sleep(1400);
        goto gunstore;
    }
    //-----GUNSTORE-----




}