xml update from listview

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C#

Hello,
I am a rookie in coding, I am trying to solve this issue for a while but seems like I couldnt get it correct. I have a user interface, user fills a combobox and a textbox which stands for rating and mailto. After they add the rule to the listview. if they press the save changes button the rules will be saved to the xml file. if they dont, it shouldnt save the rules to xml file. I read the xml document when the form loads and get the rules to the listbox but when I want to delete a rule which is already been created. I can delete it from the listview. Unfortunately the corresponding datas for that rule is still being kept at the xml file. when I run the form again the data that I erased is still at the listbox. can you help me solve that issue. here is the code;

private void WriteXML()
        {
            XmlDocument xmlDocument = new XmlDocument();
            XmlElement settings = xmlDocument.CreateElement("Settings");
            XmlElement item1 = xmlDocument.CreateElement("Timer");
            XmlElement node = xmlDocument.CreateElement("Rule");
            XmlElement node2 = xmlDocument.CreateElement("Rating");
            XmlElement node3 = xmlDocument.CreateElement("Mailto");
            item1.AppendChild(node);
            settings.AppendChild(item1);
            xmlDocument.AppendChild(settings);
            node.AppendChild(node2);
            settings.AppendChild(node);
            xmlDocument.AppendChild(settings);
            node.AppendChild(node3);
            settings.AppendChild(node);
            xmlDocument.AppendChild(settings);
            xmlDocument.Load(@"C:\Users\Orcun Iyigun\Desktop\Projects\Rules.xml");
            XmlNodeList rules = xmlDocument.SelectNodes("/Rules/Rule");
            XmlNodeList mailto = xmlDocument.GetElementsByTagName("Mailto");
            XmlNodeList rating = xmlDocument.GetElementsByTagName("Rating");
            XmlNode rulenode = xmlDocument.SelectNodes("/Rules/Rule")[0];
            XmlNode newnode = node.CloneNode(true);
             //update element values for the new node
            for (int i = 0; i < this.lvRules.Items.Count; i++)
            {
                newnode.SelectSingleNode("Mailto").InnerText = lvRules.Items[i].SubItems[1].Text;
                newnode.SelectSingleNode("Rating").InnerText = lvRules.Items[i].SubItems[0].Text;
            }           
 // append the new node to the document
            xmlDocument.DocumentElement.AppendChild(newnode);
            // update the gridview to refresh display
            XmlNodeList getrules = xmlDocument.GetElementsByTagName("Rule");
            try
            {
                xmlDocument.Save(@"C:\Users\Orcun Iyigun\Desktop\Projects\Rules.xml");
            }
            catch (Exception e)
            {
                MessageBox.Show(e.Message);
            }
        }

[modified: just fixed the pre tags]