Drving me loopy!!!

Hi I am developing a program that prints a table of student made up deatials.
The program below works ok, but when I go to enter a new detail, it lets me do it, but then I go to end the program to display the results and all I get is the last entry I did. I want the program to print all the details the user inputs, not just the most recent one.

I think the problem is my while loop in main, can anyone see where I am going worng?

Code:

---

#include <iostream>

using std::cout;
using std::endl;
using std::cin;

#include <string>

using std::string;
using std::getline;

// create directory class
class Directory
{
public:
    // constructor - sets course name
    Directory ( string name )
    {
      setListName ( name );
    }
   
    // display name of list
    void setListName ( string name )
    {
      listName = name;
    }
   
    string getListName()
    {
      return listName;
    }
   
    void displayMessage()
    {
      cout << "\tSchool list for: " << getListName();
    }
   
    // student name
    string setStudentName ( string stuName )
    {
      cin.ignore();        // prevents this function being skipped
      cout << "\n\nEnter student name: ";
      getline ( cin, stuName );
     
      studentName = stuName;
      return stuName;
    }
   
    string getStudentName()
    {
      return studentName;
    }
   
    // student date of birth
    int setDob ( int bd )
    {
      cout << "\nEnter year of birth: ";
      cin >> bd;
     
      dob = bd;
      return bd;
    }
   
    int getDob()
    {
      return dob;
    }
   
    // student gender
    char setGender ( char gen )
    {
                         
      cout << "\nEnter gender, m / f: ";
      cin >> gen;
     
      gender = gen;
      return gen;
    }
   
    char getGender()
    {
      return gender;
    }
   
private:
    string listName;        // college name
    string studentName;        // student name
    int dob; // student year of birth
    char gender; // student gender
};

// main function - driver //////////////////////////////////////////////////////
//
int main ( void )
{
  Directory dir ("MILTON COLLEGE");
  dir.displayMessage();
 
  int answer;
 
  cout << "\n\nWill you use the list: -1 to quit: ";
  cin >> answer;
 
  // quit program if no data needed
  if ( answer == -1 )
  {
      return 0;
  }
 
  // loop to input data
  while ( answer != -1 )
  {
      dir.setStudentName("");
      dir.setDob(0);
      dir.setGender('a');
     
      cout << "\nWill you add another name: -1 to show result: ";
      cin >> answer;
  }
 
  // display headings
  cout << "\nSTUDENT NAME" << "\t\t" << "D O B" << "\t\t" << "GENDER" << "\n\n";
 
  // display result of class
  cout << dir.getStudentName() << "\t\t" << dir.getDob() << "\t\t"
            << dir.getGender() << endl;
 
  cin.get();  // freeze console window
  cin.ignore();

  return 0;  // indicate program ended sucsessfuly
}

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You only have one dir. You need an instance of dir for each student.