这样的XML文件怎么生成？

[CharlesWang]

<?xml version="1.0" encoding="UTF-8"?>
<book xmlns:html="http://www.w3.org/TR/REC-html40">

</book>
以上是已经load的，我想添加一个节点<wwww html:Name="sdfsdf">sdfsdf</wwww>
我用C#应该怎样写?

[colin666]

public class XmlConfig
{
private XmlDocument doc;
private string xmlFileName;

public XmlConfig(string filename)
{
xmlFileName = filename;
doc = new XmlDocument();
try
{
doc.Load(xmlFileName);
}
catch
{
//doc.LoadXml("<?xml version=\"1.0\" encoding=\"gb2312\"?>");
}
}

public void Save()
{
try
{
doc.Save(xmlFileName);
}
catch
{
}
}

/// <summary>
/// 读XML节点
/// </summary>
/// <param name="key">节点KEY</param>
/// <param name="value">默认值</param>
/// <returns>如节点存在，返回值，否则，返回默认值</returns>
public string Read(string key, string value)
{
XmlNode node = doc.DocumentElement.SelectSingleNode(key);
if (node != null)
return node.InnerText;
else
return value;
}

/// <summary>
/// 读XML子节点
/// </summary>
/// <param name="key">父节点值</param>
/// <param name="Childkey">子节点值</param>
/// <param name="value">默认值</param>
/// <returns>如节点存在，返回值，否则，返回默认值</returns>
public string Read(string key,string Childkey,string value)
{
XmlNode node = doc.DocumentElement.SelectSingleNode(key);
if(node!=null)
{
XmlNode node2=node.SelectSingleNode(Childkey);
if(node2!=null)
{
return node2.InnerText;
}
else
return value;
}
else
return value;
}
public XmlNodeList NodeRead()
{
XmlNode node = doc.ChildNodes[1];
XmlNodeList nodelist = node.ChildNodes;
return nodelist;
}
}

[qyuhen]

XmlDocument doc = new XmlDocument();
doc.load(file);
XmlNode root = doc.SelectSingleNode("book");
XmlElement node = doc.CreateElement("wwww");
node.SetAttribute("html:name", "sdfsdf");
root.AppendChild(node);
doc.save(file);

[CharlesWang]

但是生成的文件好像是这个样子：
<?xml version="1.0" encoding="UTF-8"?>
<book xmlns:html="http://www.w3.org/TR/REC-html40">
<wwww Name="sdfsdf" xmlns="">sdfsdf</wwww>
</book>