export datagridview to xml

Question

hi dear ;
At firstly I am  fill to datagrid manually and  save as Xml ,folowing this code,But if I fill to multiple rows in datagrid and then only export last rows

for (int i = 0; i < dataGridView1.Rows.Count; i++)

                {

XmlTextWriter xmlDocument = new XmlTextWriter(@"d:\Deneme.xml", System.Text.Encoding.GetEncoding("ISO-8859-9"));

            xmlDocument.Formatting = Formatting.Indented;

            xmlDocument.Indentation = 5;

           try

            {

                xmlDocument.WriteStartDocument();               

                xmlDocument.WriteStartElement("SALES_INVOICES");               

                xmlDocument.WriteElementString("TYPE", dataGridView1.Rows[i].Cells[0].Value.ToString());

               xmlDocument.WriteEndElement();               

                xmlDocument.Close();                

                MessageBox.Show("Xml Created.");

            }

            catch (Exception ex)

            {

                  MessageBox.Show("Hata" + ex.Message);

            }

        }

And Result is 

<?xml version="1.0" encoding="iso-8859-9"?>

<SALES_INVOICES>

     <TYPE>1453</TYPE>

</SALES_INVOICES>

I want to result is ;

<?xml version="1.0" encoding="iso-8859-9"?>

<SALES_INVOICES>

     <TYPE>1452</TYPE>

</SALES_INVOICES>

     <TYPE>1453</TYPE>
</SALES_INVOICES>

Thanks in advance