How to get Employee Profile details when user clicks on employee name in tree view

protected void Page_Load(object sender, EventArgs e)
    {
        if (Session["Username"] == null)
        {
            Session["Msg"] = "Your session has expired. please login again";
            Response.Redirect("../Account/login.aspx");
            return;
        }
       
        if (!IsPostBack)
        {
            GetTreeViewItems();
        }
    }

           

    private void GetTreeViewItems()
    {
        try
        {
           string cs = ConfigurationManager.ConnectionStrings["MyConnection"].ConnectionString;
            SqlConnection con = new SqlConnection(cs);
            SqlDataAdapter da = new SqlDataAdapter("sp_GetEmployee", con);    
            DataSet ds = new DataSet();
            da.Fill(ds);

            ds.Relations.Add("ChildRows", ds.Tables[0].Columns["id"], ds.Tables[0].Columns["ManagerId"]);
            foreach (DataRow level1DataRow in ds.Tables[0].Rows)
            {
                if (string.IsNullOrEmpty(level1DataRow["ManagerId"].ToString()))
                {
                    TreeNode parentTreeNode = new TreeNode();
                    parentTreeNode.Text = level1DataRow["FirstName"].ToString();
                  // parentTreeNode.Text = level1DataRow["Designation"].ToString();
                    parentTreeNode.Value = level1DataRow["id"].ToString();

                    GetChildRows(level1DataRow, parentTreeNode);
                    TreeView1.Nodes.Add(parentTreeNode);
                }
            }
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }

    private void GetChildRows(DataRow dataRow, TreeNode treeNode)
    {
        DataRow[] childRows = dataRow.GetChildRows("ChildRows");
        foreach (DataRow childRow in childRows)
        {
            TreeNode childTreeNode = new TreeNode();
            childTreeNode.Text = childRow["FirstName"].ToString();
          // childTreeNode.Text = childRow["Designation"].ToString();
            childTreeNode.Value = childRow["id"].ToString();
            treeNode.ChildNodes.Add(childTreeNode);
            if (childRow.GetChildRows("ChildRows").Length > 0)
            {
                GetChildRows(childRow, childTreeNode);
            }
        }
    }
    protected void TreeView1_TreeNodeDataBound(object sender, TreeNodeEventArgs e)
    {
        string Prefix = "<div style="display:none;" class="çontent'">Employee</div>";
        e.Node.Text = Prefix + e.Node.Text;
    }


    protected void TreeView1_SelectedNodeChanged(object sender, EventArgs e)
    {
        
    }
}