Computing age

/// <the Summary>
/// calculate the age of the string (years of age)
/// default return: xx xx xx-year-old Japanese
/// </ the Summary>
/// <param name = "p_FirstDateTime"> 1st date parameters </ param>
/// <param name = "p_SecondDateTime"> second date parameter </ param>
/// <param name = "p_Format"> returns the string format, default: {{0} years 1} {2} month day </ param>
Private static String CalculateAgeString (the DateTime p_FirstDateTime, System.DateTime p_SecondDateTime, String p_ReturnFormat)
{
　　// determines whether the time period is positive. If it is negative, two points in time swap positions.
　　IF (System.DateTime.Compare (p_FirstDateTime, p_SecondDateTime)> 0)
　　{
　　　　System.DateTime stmpDateTime = p_FirstDateTime;
　　　　p_FirstDateTime = p_SecondDateTime;
　　　　p_SecondDateTime = stmpDateTime;
　　}

　　// returns the format string is determined. If it is empty, a default value: {1} {0} years {2} January day
　　if (string.IsNullOrEmpty (p_ReturnFormat)) p_ReturnFormat = "{0} years {2} {1} January Day";

　　// define: year, month, day,
　　int year, month, day;

　　//计算：天
　　day = p_SecondDateTime.Day - p_FirstDateTime.Day;
　　if (day < 0)
　　{
　　　　day += System.DateTime.DaysInMonth(p_FirstDateTime.Year, p_FirstDateTime.Month);
　　　　p_FirstDateTime = p_FirstDateTime.AddMonths(1);
　　}
　　//计算：月
　　month = p_SecondDateTime.Month - p_FirstDateTime.Month;
　　if (month < 0)
　　{
　　　　month += 12;
　　　　p_FirstDateTime = p_FirstDateTime.AddYears(1);
　　}
　　//计算：年
　　year = p_SecondDateTime.Year - p_FirstDateTime.Year;

　　// returns the formatted result
　　return string.Format (p_ReturnFormat, year, month The, Day);
}