private static string GetMAC()
{
string mac = String.Empty;
System.Net.NetworkInformation.NetworkInterface[] nics = System.Net.NetworkInformation.NetworkInterface.GetAllNetworkInterfaces();
if (nics.Length > 0)
mac = nics[0].GetPhysicalAddress().ToString().ToUpper();
if (mac.Length < 12)
mac = mac.PadRight(12, '0');
return String.Format("{0}:{1}:{2}:{3}:{4}:{5}",
mac.Substring(0, 2),
mac.Substring(2, 2),
mac.Substring(4, 2),
mac.Substring(6, 2),
mac.Substring(8, 2),
mac.Substring(10, 2));
}