I am getting unhandled InvalidOperationException at runtime for statemen
mySerializer.Serialize(writer, myGroup)
at line no. 6

Could anybody please helpout in excecuting this code

//<Snippet1
import System.*
import System.IO.*
import System.Xml.*
import System.Xml.Serialization.*

public class Grou

   public String groupName
   public GroupType groupType
} //Grou

public class GroupTyp

   // Use the SoapEnumAttribute to instruct the XmlSerialize
   // to generate Small and Large instead of A and B
   public int member

   public GroupType(
   
       member = 0
   } //GroupTyp

   public GroupType(int n
   
       member = n
   } //GroupTyp

   /** @attribute SoapEnum("Small"
    *
   public static int a = 0

   /** @attribute SoapEnum("Large"
    *
   public static int B = 1
} //GroupTyp

public class Ru

   public static void main(String[] args
   
       Run test = new Run()
       test.SerializeObject("SoapEnum.xml")
       test.SerializeOverride("SoapOverride.xml")
       Console.WriteLine("Fininished writing two files")
   } //mai

   private void SerializeObject(String filename
   
       // Create an instance of the XmlSerializer Class
       XmlTypeMapping mapp = (new SoapReflectionImporter())
           ImportTypeMapping(Group.class.ToType())
       XmlSerializer mySerializer = new XmlSerializer(mapp)
       // Writing the file requires a TextWriter
       TextWriter writer = new StreamWriter(filename)
       // Create an instance of the Class that will be serialized
       Group myGroup = new Group()
       // Set the object properties
       myGroup.groupName = ".NET"
       myGroup.groupType = new GroupType(GroupType.a)
       // Serialize the Class, and close the TextWriter
       mySerializer.Serialize(writer, myGroup)
       writer.Close()
   } //SerializeObjec

   private void SerializeOverride(String fileName
   
       SoapAttributeOverrides soapOver = new SoapAttributeOverrides()
       SoapAttributes SoapAtts = new SoapAttributes()
       // Add a SoapEnumAttribute for the GroupType.a enumerator.      
       // Instead of 'A'  it will be "West"
       SoapEnumAttribute soapEnum = new SoapEnumAttribute("West")
       // Override the "A" enumerator
       SoapAtts.set_SoapEnum(soapEnum)
       soapOver.Add(GroupType.class.ToType(), "A", SoapAtts)
       // Add another SoapEnumAttribute for the GroupType.B enumerator
       // Instead of //B// it will be "East"
       SoapAtts = new SoapAttributes()
       soapEnum = new SoapEnumAttribute()
       soapEnum.set_Name("East")
       SoapAtts.set_SoapEnum(soapEnum)
       soapOver.Add(GroupType.class.ToType(), "B", SoapAtts)
       // Create an XmlSerializer used for overriding
       XmlTypeMapping map = (new SoapReflectionImporter(soapOver))
           ImportTypeMapping(Group.class.ToType())
       XmlSerializer ser = new XmlSerializer(map)
       Group myGroup = new Group()
       myGroup.groupName = ".NET"
       myGroup.groupType = new GroupType(GroupType.B)
       // Writing the file requires a TextWriter
       TextWriter writer = new StreamWriter(fileName)
       ser.Serialize(writer, myGroup)
       writer.Close()
   } //SerializeOverrid
} //Ru
//</Snippet1