How to add an Element to an XML Document?

I have this:

<dockmenu>    
<photo image="images/4runner-sr5.jpg" url="www.example.com" target="_blank"><![CDATA[4Runner]]></photo>    
<photo image="images/4runner.jpg" url="www.example.com" target="_blank"><![CDATA[4Runner<br>Dock Beautiful]]></photo>    
</dockmenu>

And I need to add one more element to the xml with different information using(C# and ASP.net) so it will look like this:

<dockmenu>
<photo image="images/4runner-sr5.jpg" url="www.example.com" target="_blank"><![CDATA[4Runner]]></photo>    
<photo image="images/4runner.jpg" url="www.example.com" target="_blank"><![CDATA[4Runner<br>Dock Beautiful]]></photo>    
<photo image="images/new.jpg" url="www.new.com" target="_blank"><![CDATA[New]]></photo>    
</dockmenu>

How do I do this?

LINQ to XML:

var text = @"<dockmenu>    
<photo image=""images/4runner-sr5.jpg"" url=""www.example.com"" target=""_blank""><![CDATA[4Runner]]></photo>    
<photo image=""images/4runner.jpg"" url=""www.example.com"" target=""_blank""><![CDATA[4Runner<br>Dock Beautiful]]></photo>    
</dockmenu>";
var dockMenu= XElement.Parse(text);
var photo = new XElement("photo");
photo.SetAttributeValue("image", "images/new.jpg");
photo.SetAttributeValue("url", "www.new.com");
photo.SetAttributeValue("target", "_blank");
photo.Add(new XCData("New"));
dockMenu.Add(photo);
var newText = dockMenu.ToString();

Or, for a more concise version:

var dockMenu= XElement.Parse(text);
dockMenu.Add(
    new XElement("photo",
        new XAttribute("image", "images/new.jpg"),
        new XAttribute("url", "www.new.com"),
        new XAttribute("target", "_blank"),
        new XCData("New")));
var newText = dockMenu.ToString();

You can also add nodes to the DOM directly.

XmlDocument doc = new XmlDocument();
var text = @"<dockmenu>    
                <photo image=""images/4runner-sr5.jpg"" url=""www.example.com"" target=""_blank""><![CDATA[4Runner]]></photo>    
                <photo image=""images/4runner.jpg"" url=""www.example.com"" target=""_blank""><![CDATA[4Runner<br>Dock Beautiful]]></photo>    
             </dockmenu>";
doc.LoadXML(text);
XmlNode newChild = doc.CreateElement("photo");
XmlAttribute image = doc.CreateAttribute("image");
image.Value = "images/new.jpg";
newChild.Attributes.Append(image); 

XmlAttribute url = doc.CreateAttribute("url");
url.Value = "www.new.com";
newChild.Attributes.Append(url); 

XmlAttribute target = doc.CreateAttribute("target");
target.Value = "_blank";
newChild.Attributes.Append(target); 

XmlNode root = doc.SelectSingleNode("//dockmenu");
root.AppendChild(newChild);