Password validation

//password
#include <iostream>
#include<string.h>
#include<conio.h>
#include<stdio.h>

using namespace std;

struct password
{
    char name[100], passwords[100], userid[100];

}real, login;
int main()
{
    int i, id=1, pas=1, conf, len=0, opt;
    char confirm[100] ,a[100];

    menu:
    cout<<"\t\t\n menu"
        <<"\n\n 1. press 1 for sign in"
        <<"\n 2. press 2 for login"
        <<"\n 3. press 3 for exit";


    cout<<"\n\n enter your choice";
    cin>>opt;
    gets(a);

    switch(opt)
    {
    case 1:
        cout<<"\n enter your name :";
        gets(real.name);
        cout<<"\n enter your userid :";
        gets(real.userid);
        retype:
        cout<<"\n enter your password :";
        for(i=0;;++i)
        {
            real.passwords[i]=getch();
            cout<<"*";
            if(real.passwords[i]==13)
            break;
        }
        real.passwords[i]='\0';
        cout<<"\n retype your password to confirm it :";
        for(i=0;;++i)
        {
            confirm[i]=getch();
            cout<<"*";
            if(confirm[i]==13)
            break;
        }
        confirm[i]='\0';
        conf=strcmp(real.passwords,confirm);
            if(conf==0)
            {
                cout<<"\npassword confirmed";
            }
            else
            {
                cout<<"\nretype your password";
                goto retype;
            }
            break;

    case 2:
        log:
        cout<<"\n\n login";
        cout<<"\nenter your userid";
        gets(login.userid);
        cout<<"\nenter your password";
        for(i=0;;++i)
        {
            login.passwords[i]=getch();
            cout<<"*";
        if(login.passwords[i]==13)
        break;
        }

        login.passwords[i]='\0';

        id=strcmp(real.userid,login.userid);
        if(id==0)
        {
            pas=strcmp(real.passwords,login.passwords);
            if(pas==0)
            {
                cout<<"\t\t\n welcome";
                goto exit;
            }
            else
            {
                cout<<"your password is not correct";
                goto log;
            }
        }
        else
        {
            cout<<"your userid is incorrect";
            goto log;
        }
        break;
    case 3:
        goto exit;

    }
    goto menu;
    exit:
    return 0;
}