title: format property in class to return phone number
body: <p>Is it possible to format what I have below to return a phone number?</p>
  
  <pre><code>private string _Phone;
      [DataMember]
      public string Value
      {
          get { return String.Format("{0:(###) ###-####}", Int64.Parse(_Phone)); }
          set { _Phone = value; }
      }
  </code></pre>