急100分问一用C#写xml文件的有关问题

急!!100分问一用C#写xml文件的问题
<?xml   version= "1.0 "   encoding= "utf-8 "?>
<objects   name= "UpdateFileInfos "   xmlns= "http://www.springframework.net ">
    <object   name= "AgileIMClient.exe ">
        <property   name= "URL "   value= "http://192.168.1.195/AgileIMClient/AgileIMClient.exe "   />
        <property   name= "Version "   value= "2.0.0.0 "   />
        <property   name= "FileType "   value= ".exe "   />
        <property   name= "IsValid "   value= "true "   />
    </object>
    <object   name= "ESFramework.dll ">
        <property   name= "URL "   value= "http://192.168.1.195/AgileIMClient/ESFramework.dll "   />
        <property   name= "Version "   value= "2.0.0.0 "   />
        <property   name= "FileType "   value= ".dll "   />
        <property   name= "IsValid "   value= "true "   />
    </object>
</objects>
我想再向其中添加一个object,如:
    <object   name= "DirectX.Capture.dll ">
        <property   name= "URL "   value= "http://192.168.1.195/AgileIMClient/DirectX.Capture.dll "   />
        <property   name= "Version "   value= "2.0.0.0 "   />
        <property   name= "FileType "   value= ".dll "   />
        <property   name= "IsValid "   value= "true "   />
    </object>
用C#该怎么写???

------解决方案--------------------
static void Main()
{
System.Xml.XmlDocument xd = new System.Xml.XmlDocument();
xd.Load( @ "o.xml " );

XmlElement oElem = xd.CreateElement( "object ");//新增记录会加上xmlns= " "，不知如何去掉

oElem.SetAttribute( "name ", "DirectX.Capture.dll ");

XmlElement pElem1 = xd.CreateElement( "property ");
pElem1.SetAttribute( "name ", "URL ");
pElem1.SetAttribute( "value ", "http://192.168.1.195/AgileIMClient/DirectX.Capture.dll ");
oElem.AppendChild(pElem1);

XmlElement pElem2 = xd.CreateElement( "property ");
pElem2.SetAttribute( "name ", "Version ");
pElem2.SetAttribute( "value ", "2.0.0.0 ");
oElem.AppendChild(pElem2);

XmlElement pElem3 = xd.CreateElement( "property ");
pElem3.SetAttribute( "name ", "FileType ");
pElem3.SetAttribute( "value ", ".dll ");
oElem.AppendChild(pElem3);

XmlElement pElem4 = xd.CreateElement( "property ");
pElem4.SetAttribute( "name ", "IsValid ");
pElem4.SetAttribute( "value ", "true ");
oElem.AppendChild(pElem4);

xd.DocumentElement.AppendChild(oElem);
xd.Save( @ "o.xml " ) ;
}
------解决方案--------------------