public Department GetDepartment(Int16 departmentId)
 {
     aDepartmentGateway = new DepartmentGateway();
     List<Department> departments = new List<Department>();
     departments = GetAllDepartments();
     Department aDepartment = new Department();
     foreach (var department in departments)
     {
         if (department.DepartmentId == departmentId)
         {
             aDepartment.DepartmentId = department.DepartmentId;
             aDepartment.DepartmentCode = department.DepartmentCode;
             aDepartment.DepartmentName = department.DepartmentName;
             return aDepartment;
         }
     }
     return aDepartment;
 }
        public string SaveDepartment(Department aDepartment)
        {
            aDepartmentGateway = new DepartmentGateway();
            if (!HasThisDepartmentIdExist(aDepartment))

                if (!HasThisDepartmentNameExist(aDepartment))
                {

                    return aDepartmentGateway.SaveDepartment(aDepartment);
                }
                else
                {
                    return "This Department Name exist.";
                }

            else
            {
                return "This Department Code exist.";
            }
        }
 public List<Department> GetAllDepartments()
 {
     aDepartmentGateway = new DepartmentGateway();
     return aDepartmentGateway.GetAllDepartments();
 }