string som kun acceptere numre?

Kode 

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

namespace MCQuai
{
    class CmdMaxLimit : Command
    {
        public override string name { get { return "maxlimit"; } }
		public CmdMaxLimit() { }
        public override void Use(Player p,string message)
        {
            if (message == "") { Help(p); return; }
            int number = message.Split(' ').Length;
            if (number > 2) { Help(p); return; }
            if (number < 1) { Help(p); return; }
            if (number == 1)
            {
                {
                    int xint;

                    if (message == "") { Help(p); return; }
                    if (int.TryParse(message, out xint) == true)
                    {
                        if (Server.admins.Contains(p.name) == true)
                        {
                            if (int.TryParse(message, out xint) == true) Server.maxAdmin = xint;
                            if (xint == Server.maxAdmin) Player.GlobalMessage("Build limit has been changed to " + Server.maxAdmin + " for Admins.");
                        }
                        if (Server.operators.Contains(p.name) == true)
                        {
                            
                            if (int.TryParse(message, out xint) == true) Server.maxOp = xint;
                            if (xint == Server.maxOp) Player.GlobalMessage("Build limit has been changed to " + Server.maxOp + " for Operators.");
                        }
                    }
                }
            }
            if (number == 2)
            {
                int pos = message.IndexOf(' ');
                string t = message.Substring(0, pos).ToLower();
                string s = message.Substring(pos + 1).ToLower();
                int sint;

                if (t == "admin")
                {
                    if (s == "") { Help(p); return; }
                    if (int.TryParse(s, out sint) == true) Server.maxAdmin = sint;
                    if (sint == Server.maxAdmin) Player.GlobalMessage("Build limit has been changed to " + Server.maxAdmin + " for Admins.");
                }
                else if (t == "op")
                {
                    if (s == "") { Help(p); return; }
                    if (int.TryParse(s, out sint) == true) Server.maxOp = sint;
                    if (sint == Server.maxOp) Player.GlobalMessage("Build limit has been changed to " + Server.maxOp + " for Operators.");
                }
                else if (t == "operator")
                {
                    if (s == "") { Help(p); return; }
                    if (int.TryParse(s, out sint) == true) Server.maxOp = sint;
                    if (sint == Server.maxOp) Player.GlobalMessage("Build limit has been changed to " + Server.maxOp + " for Operators.");
                }
                else if (t == "mod")
                {
                    if (s == "") { Help(p); return; }
                    if (int.TryParse(s, out sint) == true) Server.maxMod = sint;
                    if (sint == Server.maxMod) Player.GlobalMessage("Build limit has been changed to " + Server.maxMod + " for Moderators.");
                }
                else if (t == "moderator")
                {
                    if (s == "") { Help(p); return; }
                    if (int.TryParse(s, out sint) == true) Server.maxMod = sint;
                    if (sint == Server.maxMod) Player.GlobalMessage("Build limit has been changed to " + Server.maxMod + " for Moderators.");
                }
                else if (t == "adv")
                {
                    if (s == "") { Help(p); return; }
                    if (int.TryParse(s, out sint) == true) Server.maxAdv = sint;
                    if (sint == Server.maxAdv) Player.GlobalMessage("Build limit has been changed to " + Server.maxAdv + " for Advanced Builders.");
                }
                else if (t == "advbuilder")
                {
                    if (s == "") { Help(p); return; }
                    if (int.TryParse(s, out sint) == true) Server.maxAdv = sint;
                    if (sint == Server.maxAdv) Player.GlobalMessage("Build limit has been changed to " + Server.maxAdv + " for Advanced Builders.");
                }
                else if (t == "builder")
                {
                    if (s == "") { Help(p); return; }
                    if (int.TryParse(s, out sint) == true) Server.maxBuild = sint;
                    if (sint == Server.maxBuild) Player.GlobalMessage("Build limit has been changed to " + Server.maxBuild + " for Builders.");
                }
                else { Help(p); return; }
            }
        }
        public override void Help(Player p)
        {
            p.SendMessage("/maxlimit or /ml <rank> <number> - Sets the build limit.");
        }
    }
}