Pure Virtual Error, Please Help!

[SUPERFLY]

I am trying to get both PersonType class and EmployeeType class to be abstract and the pure virtual method is to be overiddin in the derived classes.

Here is my code:

#include <iostream>
#include <iomanip>
#include <string>
#include <cctype>
#include <cstdlib>
#include <ctime>

using namespace std;

    class PersonType
    {
    private:
        string mFirstName;
	string mLastName;
	string mID;
    
    public:
	PersonType::PersonType(string firstName, string lastName, string id)
        {
            mFirstName = firstName;
	    mLastName = lastName;
	    mID = id;
	}

	virtual void PersonType::Display()
        {
			cout << "\n  Name: " << mFirstName << ", " << mLastName 
            << "\n  ID: " << mID;
        }
		virtual char PersonType::GetType(void) = 0;
    };

    class StudentType : public PersonType
    {
    private:
       
        string mProgram;

    public:
		
		char StudentType::GetType() {return 'S';}
		
		StudentType::StudentType(string firstName, string lastName, string id, string program)
            : PersonType(firstName, lastName, id)
        {
            mProgram = program; 
        }
		void StudentType::Display()
        {
			PersonType::Display();
			cout << "Program: " << mProgram;
        }
    };

    class EmployeeType : public PersonType
    {
    private:
        string mDept;
	string mDateOfHire;

    public:
        
		virtual char EmployeeType::GetType(); 

		EmployeeType::EmployeeType(string firstName, string lastName, string id, 
			string dept, string dateOfHire)
            : PersonType(firstName, lastName, id)
        {
            mDept = dept;
			mDateOfHire = dateOfHire;
        }
        
		void EmployeeType::Display()
        {
			PersonType::Display();
            cout << "\n  Dept: " << mDept; 
            cout << "\n  Date Of Hire: " << mDateOfHire;
        }
    };

    class StaffType : public EmployeeType
    {
    private:
        int mHoursWorked;
	double mPayRate;

    public:
        
	char StaffType::GetType(void) {return 'F';}
		
	StaffType::StaffType(string firstName, string lastName, string id, string dept, string dateOfHire, int hoursWorked, double payRate)
            : EmployeeType(firstName, lastName, id, dept, dateOfHire)
        {
            mHoursWorked = hoursWorked;
	    mPayRate = payRate;
        }

		void StaffType::Display()
        {
			EmployeeType::Display();
            cout << "\n  Pay: " << mPayRate * mHoursWorked; 
            
        }
    };

	class ProfessorType : public EmployeeType
	{
	private:
		
		double mSalary;

	public:
        
		char ProfessorType::GetType(void) {return 'P';}
		
		ProfessorType::ProfessorType(string firstName, string lastName, string id, string dept, 
			string dateOfHire, double salary)
			: EmployeeType(firstName, lastName, id, dept, dateOfHire)
		{
			mSalary = salary;
		}

		void ProfessorType::Display()
		{
			EmployeeType::Display();
			cout << "\n  Salary: " << mSalary; 
		}
    };

char DisplayMenu();
void AddNewPerson(string &firstName, string &lastName, string &id);
void AddNewEmployee(string &firstName, string &lastName, string &id, 
    string &dept, string &dateOfHire);
void AddNewProfessor(PersonType *personPtrAr[100], int &numPeople);
void AddNewStaff(PersonType *personPtrAr[100], int &numPeople);
void AddNewStudent(PersonType *personPtrAr[100], int &numPeople);
void DisplayEveryone(PersonType *personPtrAr[100], int numPeople);
void DisplayEmployees(PersonType *personPtrAr[100], int numPeople);
void DisplayProfessors(PersonType *personPtrAr[100], int numPeople);
void DisplayStaff(PersonType *personPtrAr[100], int numPeople);
void DisplayStudents(PersonType *personPtrAr[100], int numPeople);

void main()
{
    	
	int numPeople = 0;
    char option = ' ';
	PersonType *personPtrAr[100];
	
	cout << fixed << showpoint << setprecision(2);
    
	option = DisplayMenu();
	
	while(option != 'Q' || 'q')
    {
		switch(option)
        {
        case '1':
			AddNewStudent(personPtrAr, numPeople);
            break;
        case '2':
			AddNewStaff(personPtrAr, numPeople);
            break;
        case '3':
			AddNewProfessor(personPtrAr, numPeople);
            break;
        case '4':
            DisplayEveryone(personPtrAr, numPeople);
            break;
        case '5':
            DisplayStudents(personPtrAr, numPeople);
            break;
        case '6':
            DisplayEmployees(personPtrAr, numPeople);
			break;
        case '7':
            DisplayStaff(personPtrAr, numPeople);
            break;
		case '8':
            DisplayProfessors(personPtrAr, numPeople);
            break;
		default:
			cout << "\n\nInvalid Choice!\n\n";
			break;
        }
    }
}

char DisplayMenu()
{
	char choice = '0';

	cout << "\nDeVry University Menu\n";
    cout << "1 - Add New Student\n";
    cout << "2 - Add New Staff\n";
    cout << "3 - Add New Professor\n";
    cout << "4 - Display Everyone\n";
    cout << "5 - Display Student\n";
    cout << "6 - Display Employees\n";
	cout << "7 - Display Staff\n";
    cout << "8 - Display Professors\n";
	cout << "Q - Quit\n";	
    cout << "Enter choice: ";
	cin >> choice;
	return choice;

}
void AddNewPerson(string &firstName, string &lastName, string &id)
{
	cout << "Enter first name: ";
	cin >> firstName;
	cout << "Enter last name: "; 
	cin >> lastName;
	cout <<	"Enter ID Number: ";
	cin >> id;
}
void AddNewEmployee(string &firstName, string &lastName, string &id, 
    string &dept, string &dateOfHire)
{	
	AddNewPerson(firstName, lastName, id);
	cout << "Enter Employee's Dept: ";
	cin >> dept;
	cout << "Enter Employee's Date of Hire: ";
	cin >> dateOfHire;
}
void AddNewProfessor(PersonType *personPtrAr[], int &numPeople)
{
	string firstName = " ";
	string lastName = " ";
	string id = " ";
	string dept = " ";
	string dateOfHire = " ";
	double salary = 0.00;
	
	AddNewEmployee(firstName, lastName, id, dept, dateOfHire);
	
	cout << "Enter Professor's Salary: ";
	cin >> salary;
	
	personPtrAr[numPeople++] = new ProfessorType(firstName, lastName, id, dept, dateOfHire, salary);
}

void AddNewStaff(PersonType *personPtrAr[], int &numPeople)
{
	string firstName = " ";
	string lastName = " ";
	string id = " ";
	string dept = " ";
	string dateOfHire = " ";
	int hoursWorked = 0;
	double payRate = 0.00;

	AddNewEmployee(firstName, lastName, id, dept, dateOfHire);
	
	cout << "Enter Staff's Hours Worked: ";
	cin >> hoursWorked;
	cout << "Enter Staff's Pay Rate: ";
	cin >> payRate;
	
	personPtrAr[numPeople++] = new StaffType(firstName, lastName, id, dept, dateOfHire, hoursWorked, payRate);
	
}
void AddNewStudent(PersonType *personPtrAr[], int &numPeople)
{
	string firstName = " ";
	string lastName = " ";
	string id = " ";
	string program = " ";
	
	AddNewPerson(firstName, lastName, id);
	
	cout << "Enter Student's Program: ";
	cin >> program;
	
	personPtrAr[numPeople++] = new StudentType(firstName, lastName, id, program);
}
	

void DisplayEveryone(PersonType *personPtrAr[], int numPeople)
{
	for(int i = 0; i < numPeople; i++)
		personPtrAr[i]->Display();

}
void DisplayEmployees(PersonType *personPtrAr[], int numPeople)
{
	char type = ' ';
	
	for(int i = 0; i < numPeople; i++)
	{
		type = personPtrAr[i]->GetType();
		if(type == 'P' || 'F')
			personPtrAr[i]->Display();
	}
}
void DisplayProfessors(PersonType *personPtrAr[], int numPeople)
{
	char type = ' ';
	
	for(int i = 0; i < numPeople; i++)
	{
		type = personPtrAr[i]->GetType();
		if(type == 'P')
			personPtrAr[i]->Display();
	}
}
void DisplayStaff(PersonType *personPtrAr[], int numPeople)
{	
	char type = ' ';
	
	for(int i = 0; i < numPeople; i++)
	{
		type = personPtrAr[i]->GetType();
		if(type == 'F')
			personPtrAr[i]->Display();
	}
}
void DisplayStudents(PersonType *personPtrAr[], int numPeople)
{
	char type = ' ';
	
	for(int i = 0; i < numPeople; i++)
	{
		type = personPtrAr[i]->GetType();
		if(type == 'S')
			personPtrAr[i]->Display();
	}
}

This is the ERROR I keep getting any Help would be great, thanks.

StudentProfessorStaff.obj : error LNK2001: unresolved external symbol "public: virtual char __thiscall EmployeeType::GetType(void)" (?GetType@EmployeeType@@UAEDXZ)
C:\Documents and Settings\Administrator\My Documents\Visual Studio 2008\Projects\Week 5 i Lab\Debug\Week 5 i Lab.exe : fatal error LNK1120: 1 unresolved externals

[DSLq5Di1]

You haven't defined EmployeeType::GetType().

[savavampir]

Remove bolded part:

//virtual char PersonType::GetType(void) = 0;
virtual char GetType(void) = 0;

Also you forgot to define EmployeeType's GetType method.