C#. I need to add checking for

1) phone number. It must be in format xxx-xxx-xxxx. x is a whole number 0-9. If invalid, error message should display and user prompted to enter a valid value.

2) for month, only whole number 1-12. if invalid, error message appear and user asked to enter valid value.

3) only valid whole number based on month. If january, 1-31, feb 1-28. if invalid, error message appear and user asked to enter valid value.

4) for year, only 1960 - 2010 accepted. else, invalid message appear and user prompt to enter valid value.

using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks;

namespace FriendList { public class FriendList { public string fname, lname; public long fnumber; public int month, year, day;

public string FNAME { get { return fname; } set { fname = value; } }

public string LNAME { get { return lname; } set { lname = value; } }

public long NUMBER { get { return fnumber;

} set { fnumber = value; } }

public int MONTH

{ get { return month;

} set { if (value > 0 && value <= 12) month = value; else throw new ArgumentOutOfRangeException("Month", value, "Month must be in 1-12"); } } public int DAY { get { return day; } set { int[] daysPerMonth = { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; if (value > 0 && value <= daysPerMonth[month]) day = value; else if (month == 2 && value == 29 && (year % 400 == 0 || (year % 4 == 0 && year % 100 != 0))) day = value; else throw new ArgumentOutOfRangeException("Day", value, "invalid day"); }

public int YEAR { get { return year; } set { year = value; } }

} // open class program class Program { static void Main(string[] args) { int i, j, temp; long t; string fname, lname; FriendList[] fd = new FriendList[8]; for (i = 0; i < 8; ++i) { fd[i] = new FriendList(); Console.WriteLine(); Console.WriteLine("Enter the details for friend's phone number {0}" ,i+1 ); Console.WriteLine(); Console.WriteLine("First Name: "); fd[i].FNAME = Console.ReadLine(); Console.Write("Last Name: "); fd[i].LNAME = Console.ReadLine(); Console.Write("Mobile Number:"); fd[i].NUMBER = Convert.ToInt64(Console.ReadLine()); Console.WriteLine("Date of Birth (MM/DD/yy) : "); Console.Write("Month: "); fd[i].MONTH = Convert.ToInt32(Console.ReadLine()); Console.Write("Day: "); fd[i].DAY = Convert.ToInt32(Console.ReadLine()); Console.Write("Year: "); fd[i].YEAR = Convert.ToInt32(Console.ReadLine()); } for (i = 0; i < 8; ++i) { for (j = 0; j < 8 - i - 1; ++j) { if (String.Compare(fd[j].FNAME, fd[j + 1].FNAME) == 1) { fname = fd[j].FNAME; fd[j].FNAME = fd[j + 1].FNAME; fd[j + 1].FNAME = fname; lname = fd[j].LNAME; fd[j].LNAME = fd[j + 1].LNAME; fd[j + 1].LNAME = lname; t = fd[j].NUMBER; fd[j].NUMBER = fd[j + 1].NUMBER; fd[j + 1].NUMBER = t; temp = fd[j].DAY; fd[j].DAY = fd[j + 1].DAY; fd[j + 1].DAY = temp; temp = fd[j].MONTH; fd[j].MONTH = fd[j + 1].MONTH; fd[j + 1].MONTH = temp; temp = fd[j].YEAR; fd[j].YEAR = fd[j + 1].YEAR; fd[j + 1].YEAR = temp;

} } } Console.WriteLine(); Console.WriteLine(); for (i = 0; i < 8; ++i) { Console.WriteLine("The information of friend's number {0} is: ", i + 1); Console.WriteLine(); Console.WriteLine("NAME: {0} {1}", fd[i].FNAME, fd[i].LNAME); Console.WriteLine("PHONE NUMBER {0} ", fd[i].NUMBER); Console.WriteLine(); Console.WriteLine("Date of Birth MM/DD/YY: {0}/{1}/{2} ", fd[i].MONTH, fd[i].DAY,fd[i].YEAR); Console.WriteLine(); } Console.ReadLine(); } }