Smart Card Problem

Question

Hi all.. I am using VS.net 2003(C#) and OMKEY smart card reader.Up to SardStatus my application working fine. But when i want to read smart card's chip number it's giving an error like "Can not marshal parameter #2: The type definition of this type has no layout information." part of my code: [DllImport("WINSCARD.DLL")] internal static extern uint SCardTransmit(int hCard, SCARD_IO_REQUEST pioSendPci, byte[] pbSendBuffer, int cbSendLength, string recvPci,byte[] pbRecvBuffer, ref int pcbRecvLength); public string GetChipno(int card_Handle) { //00A40000024000 byte[] pbSendBuffer = {0x00,0xCA,0x00,0x00,0x02,0x46,0x00}; //int cbSendLength=13; //IntPtr SCARD_PCI_IO=GetPciT0(); const uint SCARD_PROTOCOL_T0=1; SCARD_IO_REQUEST SCARD_PCI_T0=new SCARD_IO_REQUEST(); SCARD_PCI_T0.dwProtocol=SCARD_PROTOCOL_T0; SCARD_PCI_T0.cbPciLength=8; SCARD_IO_REQUEST gpioRecevPCI=new SCARD_IO_REQUEST(); gpioRecevPCI.dwProtocol=SCARD_PROTOCOL_T0; gpioRecevPCI.cbPciLength=8; int cbSendLength=5; int pcbRecvLength=2; byte[] pbRecvBuffer=new byte[50]; try { uint errors = SCardTransmit(card_Handle,SCARD_PCI_T0, pbSendBuffer, cbSendLength,null, pbRecvBuffer, ref pcbRecvLength); System.Text.ASCIIEncoding ascEnd=new System.Text.ASCIIEncoding(); string lreader3=ascEnd.GetString(pbRecvBuffer,0,10); } catch(Exception ex) { return ex.Message; } Plzz help me out......