using System;

using System.Threading.Tasks;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {   

        var Names = new List<string> { "John", "Andrew", "Mike" ,"Steve" ,"Jason" };

        string nullString = null;

        var results = Names.Contains(nullString.ToLower());

    }

}