private void AddNewDoctorExecute()
 {
     try
     {
         AddDoctorView addDoctor = new AddDoctorView();
         addDoctor.ShowDialog();
     }
     catch (Exception ex)
     {
         MessageBox.Show(ex.ToString());
     }
 }
 /// <summary>
 /// This method invokes method for opening a window for adding doctor.
 /// </summary>
 public void AddExecute()
 {
     try
     {
         AddDoctorView form = new AddDoctorView();
         form.ShowDialog();
         DoctorList = doctors.ViewAllDoctors();
     }
     catch (Exception ex)
     {
         MessageBox.Show(ex.ToString());
     }
 }