private void BtnSave_Click(object sender, RoutedEventArgs e)
        {
            Employee employee = new Employee();

            employee.Id        = Convert.ToInt32(tbxId.Text);
            employee.FirstName = tbxFirstName.Text;
            employee.LastName  = tbxLastName.Text;

            if (employee.Id == 0)//insert
            {
                int sonuc = employee.Insert();

                if (sonuc > 0)
                {
                    //Son kayidi getir Employee Id sini ogren!
                    Employee sonEmploye = Employee.SelectLastEmployee();

                    int employeeRoleKayitSayisi = 0;
                    int isaretliRoleSayisi      = 0;
                    foreach (CheckBox itemChkEmployeeRole in lstEmployeeRoles.Items)
                    {
                        if ((bool)itemChkEmployeeRole.IsChecked)
                        {
                            isaretliRoleSayisi++;

                            EmployeeRole yeniEmployeeRole = new EmployeeRole();
                            yeniEmployeeRole.RoleId     = Convert.ToInt32(itemChkEmployeeRole.Tag);
                            yeniEmployeeRole.EmployeeId = sonEmploye.Id;
                            employeeRoleKayitSayisi     = employeeRoleKayitSayisi + yeniEmployeeRole.Insert();
                        }
                    }

                    if (employeeRoleKayitSayisi == isaretliRoleSayisi)
                    {
                        LoadEmployeesGrid();
                        MessageBox.Show("Kayit basarili.");
                        BtnNew_Click(null, null);
                    }
                }
                else
                {
                    MessageBox.Show("Hay aksi!!!!");
                }
            }
            else if (employee.Id > 0) //update
            {
                int sonuc = employee.Update();
                if (sonuc > 0)
                {
                    //1.Adim Mevcut EmployeeRolelerini Sonlandir(Status = false ve EndDate ver.)
                    int sonlananRoleSayisi = EmployeeRole.DisableEmployeeRoleWithEmployeeId(employee.Id);
                    //2.Adim Secili olan CheckBoxtaki rolleri insert et.
                    int employeeRoleKayitSayisi = 0;
                    int isaretliRoleSayisi      = 0;
                    foreach (CheckBox itemChkEmployeeRole in lstEmployeeRoles.Items)
                    {
                        if ((bool)itemChkEmployeeRole.IsChecked)
                        {
                            isaretliRoleSayisi++;

                            EmployeeRole yeniEmployeeRole = new EmployeeRole();
                            yeniEmployeeRole.RoleId     = Convert.ToInt32(itemChkEmployeeRole.Tag);
                            yeniEmployeeRole.EmployeeId = employee.Id;
                            employeeRoleKayitSayisi     = employeeRoleKayitSayisi + yeniEmployeeRole.Insert();
                        }
                    }

                    if (employeeRoleKayitSayisi == isaretliRoleSayisi)
                    {
                        LoadEmployeesGrid();
                        MessageBox.Show("Update basarili.");
                        BtnNew_Click(null, null);
                    }
                }
            }
        }