How to add xmlnamespace to a xmldocument

Question

Im trying to create a xml the should look like this

Answer 1

XmlDocument xmlDocSPack = new XmlDocument();
XmlNode xmldocNode = xmlDocSPack.CreateXmlDeclaration("1.0", "", null);
xmlDocSPack.AppendChild(xmldocNode);

XmlElement LiftsMainNode = xmlDocSPack.CreateElement("Lifts");
LiftsMainNode.SetAttribute("xmlns:xsi", "http://www.w3.org/2001/XMLSchema-instance");

xmlDocSPack.AppendChild(LiftsMainNode);
xmlDocSPack.Save("SPack"+DateTime.Now.Year + ".xml");

Output :