feedback system using xmldatasource. Help on gridview..

Hi all ,
i want to create feedback system where em using textboxes to capture name, emailid, cnt number, description like fields.
now i want these values to be entered into xml file and a gridview is been bind to this xml file so that i can view the sent messages.
my codes..

<asp:GridView ID="GridView1" runat="server">
        </asp:GridView>
        <asp:XmlDataSource ID="XmlDataSource1" runat="server" DataFile="~/XMLFile2.xml" XPath="/gridview/message">
        </asp:XmlDataSource>

protected void Page_Load(object sender, EventArgs e)
    {
          DataSet ds1 = new DataSet();
         ds1.ReadXml(Server.MapPath("XMLFile2.xml"));
         GridView1.DataSource = ds1;
         GridView1.DataBind();
        
    }

    protected void btnSend_Click(object sender, EventArgs e)
    {
        XmlDocument doc = new XmlDocument();
        doc.Load(@"C:\Users\anil\Documents\Visual Studio 2010\WebSites\WebSite12\XMLFile2.xml");
        XmlElement root = doc.CreateElement("Message");
        XmlElement FirstName = doc.CreateElement("FirstName");
        XmlElement EmailID = doc.CreateElement("EmailID");
        XmlElement ContactNumber = doc.CreateElement("ContactNumber");
        XmlElement Description = doc.CreateElement("Description");
        FirstName.InnerText = txtName.Text;
        EmailID.InnerText = txtEmailID.Text;
        ContactNumber.InnerText = txtCntNum.Text;
        Description.InnerText = txtMessage.Text;
        root.AppendChild(FirstName);
        root.AppendChild(EmailID);
        root.AppendChild(ContactNumber);
        root.AppendChild(Description);
        doc.DocumentElement.AppendChild(root);
        doc.Save(@"C:\Users\anil\Documents\Visual Studio 2010\WebSites\WebSite12\XMLFile2.xml");
        txtName.Text = "";
        txtEmailID.Text ="";
        txtCntNum.Text ="" ;
        txtMessage.Text = "";
        
           }
}

Thanks & Regards;
aaa