Retrieve Client PC MAC address

using Microsoft.Win32;

using System;

using System.Collections.Generic;

using System.Management;

using System.Net.NetworkInformation;

using System.IO;

public string GETMAC()

        {

            string macadd = "";

            NetworkInterface[] nics = NetworkInterface.GetAllNetworkInterfaces();

            PhysicalAddress address = nics[0].GetPhysicalAddress();

            byte[] bytes = address.GetAddressBytes();

            for (int i = 0; i < bytes.Length; i++)

            {

                macadd += bytes[i].ToString("X2");

                if (i != bytes.Length - 1)

                {

                    macadd += ":";

                }

            }

            return macadd;

        }