populate a combbox with attributes of a selected xmlnode using c#

Question

Im using c#.net windows form application. I have a xml file. I have loaded unique node names into a tree view. Here is the xml file: Hello.xml - - abc hello how ru - def i m fine - ghi how abt u - asd aaaaaaaaa

I have loaded the node names into a tree view. The code I have used is:

string xmlfilename = ""; private void button1_Click(object sender, EventArgs e) {

        try
        {


            string strRootNode = "resourceRoot";

            OpenFileDialog Dlg = new OpenFileDialog();
            Dlg.Filter = "All files(*.*)|*.*|xml file (*.xml)|*.txt";
            Dlg.CheckFileExists = true;



            if (Dlg.ShowDialog() == DialogResult.OK)
            {
                xmlfilename = Dlg.FileName;

            }


            // Load the XML file.
            //XmlDocument dom = new XmlDocument();
            //dom.Load(xmlfilename);

            XmlDocument doc = new XmlDocument();
            doc.Load(xmlfilename);
            //this will give the root name
            string rootName = doc.SelectSingleNode("/*").Name;
            textBox4.Text = rootName.ToString();
            //XmlNode root = dom.LastChild;
            //textBox4.Text = root.Name.ToString();

            //List<String> listOfNodes = new List<string>();

            // Load the XML into the TreeView.
            this.treeView1.Nodes.Clear();
            this.treeView1.Nodes.Add(new TreeNode(strRootNode));
            TreeNode mytreeNode = new TreeNode();
            mytreeNode = this.treeView1.Nodes[0];

            XmlNodeList oNodes = doc.SelectNodes(textBox4.Text);


            XmlNode myxmlNode = oNodes.Item(0);
            TreeNode tNewNode = new TreeNode(myxmlNode.Name);
            mytreeNode.Nodes.Add(tNewNode);

            AddNode(ref myxmlNode, ref tNewNode);

            //this.treeView1.CollapseAll();
            //this.treeView1.Nodes[0].Expand();
            //this.Cursor = System.Windows.Forms.Cursors.Default;

        }

        catch (Exception ex)
        {
            this.Cursor = System.Windows.Forms.Cursors.Default;

        }
    }







    private void AddNode(ref XmlNode inXmlNode, ref TreeNode inTreeNode)
    {
        try
        {
            // Recursive routine to walk the XML DOM and add its nodes to a TreeView.
            XmlNode xNode;
            TreeNode tNode;
            XmlNodeList nodeList;
            int i;

            // Loop through the XML nodes until the leaf is reached.
            // Add the nodes to the TreeView during the looping process.

            if (inXmlNode.HasChildNodes)
            {
                nodeList = inXmlNode.ChildNodes;
                List<string> nodeNames = new List<string>();

                for (i = 0; i < nodeList.Count; i++)
                {
                    xNode = inXmlNode.ChildNodes[i];


                    //if (xNode.NodeType != (XmlNodeType.Text))
                    //{
                    //if (inTreeNode.Nodes.Contains( xNode.Name))
                    //{
                    //listOfNodes.Add(xNode.Name.ToString());

                    if (xNode.HasChildNodes)
                    {
                        if (!(nodeNames.Contains(xNode.Name.ToString())))
                        {
                            inTreeNode.Nodes.Add(new TreeNode(xNode.Name));


                            tNode = inTreeNode.Nodes[inTreeNode.Nodes.Count - 1];

                            //if ((listOfNodes.Contains(tNode.Name.ToString())))
                            //{

                            AddNode(ref xNode, ref tNode);

                            //}
                            nodeNames.Add(xNode.Name.ToString());

                        }
                    }
                }
            }
            else
            {
                //MessageBox.Show("not working");
                inTreeNode.Text = inXmlNode.OuterXml.Trim();
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message, "Error");
        }
    }

AND THE OUTPUT OF THE TREE VIEW IS: -resourceRoot -languages language key value name firstname middlename

Now my problem is if I select key, I need to populate the combobox with these values: abc def ghi

I mean to say all the values in the key node. Please suggest me with a proper code.