title: Regex for my password validation
body: <p>I need a regular expression for my password format. It must ensure that password only contains letters a-z, digits 0-9 and special characters: .@#$%&amp;.
  I am using .NET C# programming language.
  This is my code:</p>
  
  <pre><code>Regex userAndPassPattern = new Regex("^[a-z0-9.@#$%&amp;]$");
  if (!userAndPassPattern.IsMatch(username) || !userAndPassPattern.IsMatch(password))
      return false;
  </code></pre>
  
  <p>The problem is that I always get back false.</p>