TXT to HTML translator - Practice Exercises C# Sharp

using System;
using System.IO;
namespace TXTtoHTML
{
    class Program
    {
        static void Main()
        {
            Console.Write("Enter name of file: ");
            string nameFileTxt = Console.ReadLine();
            string nameFileHtml = nameFileTxt.Substring(0, nameFileTxt.Length - 4);

            if (File.Exists(nameFileTxt))
            {
                StreamReader myfileTxt;
                StreamWriter myfileHtml;

                myfileTxt = File.OpenText(nameFileTxt);
                myfileHtml = File.CreateText(nameFileHtml + ".html");
                string line;

                myfileHtml.WriteLine("");
                myfileHtml.WriteLine("");
                myfileHtml.WriteLine("");
                myfileHtml.WriteLine("");
                myfileHtml.WriteLine("");
                do
                {
                    line = myfileTxt.ReadLine();
                    if (line != null)
                        myfileHtml.WriteLine("" + line + "");
                }
                while (line != null);

                myfileHtml.WriteLine("");
                myfileHtml.WriteLine("");

                myfileTxt.Close();
                myfileHtml.Close();
            }
        }
    }
}