Csharp/C Sharp by API/System.Xml.Linq/XCData

new XCData

  
using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
using System.Xml;
using System.Xml.Linq;
public class MainClass {
    public static void Main() {
        XElement xErrorMessage = new XElement("HTMLMessage",new XCData("<H1>Invalid password.</H1>"));
        Console.WriteLine(xErrorMessage);
    }
}