Please help correct the Java error below:

Error:

Exception in thread "main" java.lang.Error: Unresolved compilation problems:

TaxNonExemptCustomer cannot be resolved to a type

TaxExemptCustomerClass cannot be resolved to a type

at Program8.main(Program8.java:341)

Code:

import java.io.File;

import java.io.FileNotFoundException;

import java.util.Scanner;

public class Program8 {

public class OfficeCustomerClass {

private String nameElement;

private int id = 0;

private double billBalanceElement;

private String email;

public OfficeCustomerClass()

{

nameElement="";

id=0;

billBalanceElement=0;

email="";

}

public class TaxExemptCustomerClass extends OfficeCustomerClass{

private String taxLiabilityElement;

public TaxExemptCustomerClass()

{

super();

taxLiabilityElement= "";

}

public TaxExemptCustomerClass(String nameElement, int id, double billBalanceElement, String email,String taxLiabilityElement)

{

super(nameElement,id,billBalanceElement,email);

this.taxLiabilityElement = taxLiabilityElement;

}

public void settaxLiabilityElement(String taxLiabilityElement)

{

this.taxLiabilityElement = taxLiabilityElement;

}

public String gettaxLiabilityElement()

{

return taxLiabilityElement;

}

public String toString()

{

return (super.toString()+"\t"+taxLiabilityElement);

}

}

public class TaxNonExemptCustomer extends OfficeCustomerClass{

private double taxLiabilityElement;

public TaxNonExemptCustomer()

{

super();

taxLiabilityElement=0;

}

public TaxNonExemptCustomer(String nameElement, int id, double billBalanceElement, String email,double taxLiabilityElement)

{

super(nameElement,id,billBalanceElement,email);

settaxLiabilityElement(taxLiabilityElement);

}

public void settaxLiabilityElement(double taxLiabilityElement)

{

this.taxLiabilityElement = ((taxLiabilityElement*getbillBalanceElement())/100);

}

public double gettaxLiabilityElement()

{

return taxLiabilityElement ;

}

public String toString()

{

return(super.toString()+"\t"+taxLiabilityElement);

}

}

//

public OfficeCustomerClass(String nameElement, int id, double billBalanceElement, String email)

{

this.nameElement = nameElement;

this.id = id;

this.billBalanceElement = billBalanceElement;

this.email = email;

}

public void setnameElement(String nameElement)

{

this.nameElement = nameElement;

}

public void setId(int id)

{

this.id = id;

}

public void setbillBalanceElement(double billBalanceElement)

{

this.billBalanceElement = billBalanceElement;

}

public void setEmail(String email)

{

this.email = email;

}

public String getnameElement()

{

return nameElement;

}

public int getId()

{

return id;

}

public double getbillBalanceElement()

{

return billBalanceElement;

}

public String getEmail()

{

return email;

}

public String toString()

{

return (nameElement+"\t"+id+"\t"+billBalanceElement+"\t\t"+email);

}

}

public static void sort(OfficeCustomerClass customersObject[],int index)

{

int min;

for (int i = 0; i < index; i++)

{

min = i;

for (int j = i + 1; j < index; j++)

if (customersObject[j].getId() < customersObject[min].getId())

min = j;

if (min != i)

{

OfficeCustomerClass temp = customersObject[i];

customersObject[i] = customersObject[min];

customersObject[min] = temp;

}

}

}

public static void main(String[] args) throws FileNotFoundException {

OfficeCustomerClass customersObject[];

File file = new File("OfficeCustomerClass.txt");

Scanner fileScan = new Scanner(file);

int records;

records = Integer.parseInt(fileScan.nextLine());

customersObject = new OfficeCustomerClass[records];

int index = 0;

String nameElement = "", email = "", taxLiabilityElement = "";

int id = 0;

double bill = 0;

while (fileScan.hasNext() && index < records)

{

String line = fileScan.nextLine();

String words[] = line.split(" ");

try {

nameElement = words[0];

id = Integer.parseInt(words[1]);

bill = Double.parseDouble(words[2]);

email = words[3];

taxLiabilityElement = words[4];

double tax = Double.parseDouble(taxLiabilityElement);

customersObject[index] = new TaxNonExemptCustomer(nameElement, id, bill, email, tax);

index++;

} catch (NumberFormatException ex)

{

customersObject[index] = new TaxExemptCustomerClass(nameElement, id, bill, email, taxLiabilityElement);

index++;

}

}

fileScan.close();

sort(customersObject,index);

int page = 0;

int i = 0;

while (i < index) {

page++;

int j = 0;

System.out.println(" \t Office Supplies Inc \t Page : " + page);

System.out.println("Customer Name \t ID \t Bill balance \t email \t\t Tax Liability");

// displaying 2 records per page, change this to display the desired

// number of records per page

while (i < customersObject.length && j < 2) {

System.out.println(customersObject[i]);

i++;

j++;

}

}

}

}