This image shows the sequence of events that occurs when you query for information about an 
employee.
- The application sends the request to the Controller servlet.
 
- The Controller invokes the getInstance and createActionHandler methods on the 
ActionHandlerFactory, and the performAction method on the QueryEmployee.
 
- If the employee ID is invalid, QueryEmployee forwards 
the request to a JSP error page, which returns an error response to the client.
 
- If the employee ID is valid, QueryEmployee forwards the request to the queryEmployee 
JSP.
 
- The queryEmployee JSP calls getEmployeeManager on the SessionHelper bean and 
getEmployeeDetails on the EmployeeManager bean.
 
- The EmployeeManager then calls getEmployee, which in turn calls findByPrimaryKey on the 
Employee entity bean.
 
- The Employee entity bean calls new, findByPrimaryKey, and load on  
EmployeeDAOImpl.
 
- EmployeeDAOImpl calls new and setBenefits on MutableEmployeeModel, 
and calls new on BenefitItem.
 
- EmployeeManager now calls getDetails on Employee, which returns an EmployeeModel.
 
- When all of the information is gathered, the application passes it back to the 
queryEmployee JSP, which returns the information to the client.