do {

    cout << "\t\t------------------\n";
    cout << "\t\tLOGIN CREDENTIALS\n";
    cout << "\t\t------------------\n";

    cout << "Enter Username : ";
    cin >> username;

    cout << "Enter Password : ";
    cin >> password;

    if((username == USERNAME && password == PASSWORD) || (username == USERNAME1 && password == PASSWORD1)
      || (username == USERNAME2 && password == PASSWORD2) || (username == USERNAME3 && password == PASSWORD3)) {
        insert=true;
    } else {
        //cout<<"Incorrect user and password. Try again."<<endl;
        attemps++;
      }

  } while(insert == false && attemps < 3);

  if (insert == false) {
    cout <<"Failed. Bye"<<endl;
    exit(1);
  }
  else {
    cout<<"\n"<<endl;
    cout<<"\nSuccesful authentication!"<<endl;
    cout<<"\n"<<endl;
  }

}