public void AddTwoValues()
{
    try
    {
        CString strValue1 = m_mainForm.GetFirstTextBoxValue();
        CString strValue2 = m_mainForm.GetSecondTextBoxValue();

        int iValue1 = strValue1.ToInteger();
        int iValue2 = strValue2.ToInteger();
        int iResult = iValue1 + iValue2;
        CString strShowResult = CString.ValueOf(iResult);
        m_mainForm.ShowResult(strShowResult);
        CString strSaveResult = new CString(strValue1.GetValue() + " + " + strValue2.GetValue() + " = " + strShowResult.GetValue() + "\n");
        m_mainForm.SaveResult(strSaveResult);
    }
    catch (Exception ee)
    {
        m_mainForm.SaveResult(new CString(ee.Message + "\n"));
        m_mainForm.ShowResult(new CString("Error"));
    }
}