How to get Mac Address of Client System in asp.net

Hello,

How to get Max Address of a client system in asp.net?

public string MacAddress()

{

NetworkInterface[] nif = NetworkInterface.GetAllNetworkInterfaces();

String MACAddress = string.Empty;

foreach (NetworkInterface adapter in nif)

{

if (MACAddress == String.Empty)

{

IPInterfaceProperties ipproperties = adapter.GetIPProperties();

MACAddress = adapter.GetPhysicalAddress().ToString();

}

return MACAddress;

}

When i try this code, it returns same Mac Address in different system in one network.

Please help...