ASP.Net : Xml Version Format

Question

Hi Experts,

My Xml format is :

<Sis>
  <Student>
    <StudentID>1</StudentID>
    <AcademicDetails>2008-2009</AcademicDetails>
    <PersonalDetails>
      <FirstName>Vijay</FirstName>
      <MiddleName>Laxmanrao</MiddleName>
      <LastName>Jadhav</LastName>
    </PersonalDetails>
  </Student>
</Sis>

I have seen lot of Xml's with Version information ie <? xml version="1.0" ?>.

My question is that what is a cause that my Xml didn't show version and other information.

My Sample code behind for creating Xml is :

        #region Create Student Xml String
        /* ---------------------------------------------------------- Create Student Xml File --------------------------------------------------------------------- */

        private string sCreateStudentXml()
        {
            try
            {
                Consumer.Sis studentDS = new Consumer.Sis();
                Sis.StudentRow student_row = studentDS.Student.NewStudentRow();

                student_row.StudentID = 1;
                student_row.AcademicDetails = "2008-2009";

                studentDS.Student.AddStudentRow(student_row);

                Sis.PersonalDetailsRow sub_StudentPersonalDetails_row = studentDS.PersonalDetails.NewPersonalDetailsRow();

                sub_StudentPersonalDetails_row.FirstName = "Vijay";
                sub_StudentPersonalDetails_row.MiddleName = "Laxmanrao";
                sub_StudentPersonalDetails_row.LastName = "Jadhav";
                sub_StudentPersonalDetails_row.StudentRow = student_row;
                studentDS.PersonalDetails.AddPersonalDetailsRow(sub_StudentPersonalDetails_row);

                // Accept the changes
                studentDS.AcceptChanges();

                System.IO.StringWriter writer = new System.IO.StringWriter();

                studentDS.WriteXml(writer, System.Data.XmlWriteMode.WriteSchema);
                return writer.ToString();
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }

        #endregion

And my Xsd is :

<?xml version="1.0" encoding="utf-8" ?>
<!--Created with Liquid XML Studio - 30 Day Trial Edition (http://www.liquid-technologies.com)-->
<xsd:schema id="Sis" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <xsd:complexType name="StudentPersonalDetails">
    <xsd:sequence>
      <xsd:element name="FirstName" type="xsd:string" />
      <xsd:element name="MiddleName" type="xsd:string" />
      <xsd:element name="LastName" type="xsd:string" />
    </xsd:sequence>
  </xsd:complexType>
  <xsd:complexType name="StudentType">
    <xsd:sequence>
      <xsd:element name="StudentID" type="xsd:int" />
      <xsd:element name="AcademicDetails" type="xsd:string" />
      <xsd:element name="PersonalDetails" type="StudentPersonalDetails" />
    </xsd:sequence>
  </xsd:complexType>
  <xsd:complexType name="ParentPersonalDetails">
    <xsd:sequence>
      <xsd:element name="FirstName" type="xsd:string" />
      <xsd:element name="MiddleName" type="xsd:string" />
      <xsd:element name="LastName" type="xsd:string" />
    </xsd:sequence>
  </xsd:complexType>
  <xsd:complexType name="ParentType">
    <xsd:sequence>
      <xsd:element name="ParentID" type="xsd:int" />
      <xsd:element name="ParentPersonalDetails" type="ParentPersonalDetails" />
    </xsd:sequence>
  </xsd:complexType>
  <xsd:element name="Sis">
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element name="Student" type="StudentType" />
        <xsd:element name="Parent" type="ParentType" />
      </xsd:sequence>
    </xsd:complexType>
  </xsd:element>
</xsd:schema>

Please help! If anyone know please reply.

Note : I have created above Xml against Xsd.

Thanks.