About XML Tag

Hi Everybody ;

I want to create a xml file using C# and I have some problem ,my method thus ;

xmlDocument.WriteStartElement("SALES_INVOICES");

xmldocument.WriteEndElement();

the  Result  is    </SALES_INVOICES>

</SALES_INVOICES>

I Want to  result is for WriteStartElement  </SALES_INVOICES> and  WriteEndElement for   </INVOICES>

Thanks in advance .