title: c# != operator not functioning correctly
body: <p>I don't know if it is just me being thick but I have a bit of validation code to check for a yes or no answer. </p>
  
  <p>I can't seem to get it to work I have used the code in other places in my program and it works but I can't spot the error if there is one. The code runs through the while anyway no mater what the input character is.</p>
  
  <pre><code>string correctDestenation = Console.ReadLine().ToLower();
  while (correctDestenation != "y" || correctDestenation != "n")
  {
      Console.WriteLine(
          "Oops! You must enter a 'y' for yes and a 'n' for no");
      correctDestenation = Console.ReadLine().ToLower();
  }
  </code></pre>