How to neglect Capital and small alphabet in all

Question

string usertype;
usertype = Console.ReadLine();

if (usertype== "Yahoo")
{ 
  Console.WriteLine("You typed Yahoo therefore we are now login to Yahoo Page");
  Console.ReadLine();
}

Nothing wrong with t he code except: If user types Yahoo then it shows answer. I want user; if he types yahoo then answer should be the same.

Answer 1

string usertype;
usertype = Console.ReadLine();

if (string.Equals(usertype,"Yahoo",StringComparison.OrdinalIgnoreCase))
{ 
  Console.WriteLine("You typed Yahoo therefore we are now login to Yahoo Page");
  Console.ReadLine();
}