SOS...

Hi ,how are you , may i hava your help to an application in java?The
program prints the information of the employees , salary,
rate ,name...The main program called BasePlusCommissionEmployeeTest3
is:
public class BasePlusCommissionEmployeeTest3{
    public static void main(String[] args){
        BasePlusCommissionEmployee3 basePlusCommissionEmployee =new
BasePlusCommissionEmployee3("Bob","Lewis","333-33-3333",5000,.04,300);
        System.out.println("ergates\n");
        System.out.printf("%s %s\n","first
name=",basePlusCommissionEmployee.getFirstName());
        System.out.printf("%s %s
\n","lastName",basePlusCommissionEmployee.getLastName());
        System.out.printf("%s %s
\n","ssn=",basePlusCommissionEmployee.getSocialSecurityNumber());
        System.out.printf("%s %.2f\n","gross
sales=",basePlusCommissionEmployee.getGrossSales());
        System.out.printf("%s %.2f\n","com
rate=",basePlusCommissionEmployee.getCommissionRate());
        System.out.printf("%s %.2f
\n",basePlusCommissionEmployee.getBaseSalary());
        basePlusCommissionEmployee.setBaseSalary(1000);
        System.out.printf("\n%s: \n\n%s\n","o
ergaths:",basePlusCommissionEmployee.toString());
    }
}
and calls class BasePlusCommissionEmployee3:
public class BasePlusCommissionEmployee3 extends COMEMP{
    private double baseSalary;
    public BasePlusCommissionEmployee3(String first,String last,String
ssn,double sales,double rate ,double salary){
      super(first,last,ssn,sales,rate);
      setBaseSalary(salary);
    }
    public void setBaseSalary(double salary){
        baseSalary=(salary<0.0)?0.0:salary;

    }
    public double getBaseSalary(){
        return baseSalary;
    }
    public double earnings(){
        return baseSalary+(commissionRate*grossSales);
    }
    public String toString(){
        return String.format("%s: %s %s/n%s: %s\n%s: %.2f\n%s: %.2f\n%s: %.
2f","o ergazomenos:",firstName,lastName,
        "ssn=",socialSecurityNumber,"grossSales",grossSales,"commissionRate",
        commissionRate,"base salary",baseSalary);

    }
}
that calls class COMEMP: public class COMEMP{
    protected String firstName;
    protected String lastName;
    protected String socialSecurityNumber;
    protected double grossSales;
    protected double commissionRate;
    public COMEMP(String first,String last,String ssn,double
sales ,double rate){
       firstName=first;
        lastName=last;
        socialSecurityNumber=ssn;
        setGrossSales(sales);
        setCommissionRate(rate);

    }
    public void setFirstName(String first){
        firstName=first;
    }
    public String getFirstName(){
        return firstName;
    }
    public void setLastName(String last){
        lastName=last;
    }
    public String getLastName(){
        return lastName;
    }
    public void setSocialSecurityNumber(String ssn){
        socialSecurityNumber=ssn;
    }
    public String getSocialSecurityNumber(){
        return socialSecurityNumber;
    }
    public void setGrossSales(double sales){
        grossSales=(sales<0.0)?0.0:sales;
    }
    public double getGrossSales(){
        return grossSales;
    }
    public void setCommissionRate(double rate){
        commissionRate=(rate>0.0&&rate<1.0)?rate:0.0;
    }
    public double getCommissionRate(){
        return commissionRate;
    }
    public double earnings(){
        return commissionRate*grossSales;
    }
    public String toString(){
        return String.format("%s: %s %s\n%s: %s\nn%s: %.2f\n%s: %.2f
","commission
employee",firstName,lastName,"ssn",socialSecurityNumber,"gross
sales",grossSales,"rate",commissionRate);
    }
}
Compilation is successfully but runtime error says: