public struct TCardOperator
        {
           public string CardType;
           public string FileName;
           //public int Handle;
           [DllImport("MICARD.dll", CharSet = CharSet.None)]
           public static extern void ReadICFixSL(int ICType, StringBuilder SLBuf, StringBuilder Result, ref int iRetValue);
           [DllImport("MICARD.dll", CharSet = CharSet.None)]
           public static extern int GetMIVersion(StringBuilder lpDLLVersion, StringBuilder lpDRVVersion, StringBuilder              ReaderVersion, StringBuilder lpResult);
           [DllImport("MICARD.dll", CharSet = CharSet.None)]
           public static extern void SetCallback(TCallBack lpCallback);
         }