Create a class called Employee that includes three pieces of information as instance variables — a first name (type string), a last name (type string) and a monthly salary (double). Your class should have two constructors, one default and one that initializes the three values. Provide the properties with a get and set accessor for all instance variables. If the monthly salary is negative, the set accessor should leave the instance variable unchanged.
Write a test application named EmployeeTest that demonstrates class Employee’s capabilities. Create two Employee objects and display each object’s yearly salary. Then give each Employee a 10% raise and display each Employee’s yearly salary again.