title: how to apply text watermark to text box in xaml (windows 8 metrro app)
body: <p>I am workng on windows 8 app getting problem to use text watermark to text box, can anybody help me to find out how we can apply water mark init .</p>
  
  <p>below is the code of  my text box.</p>
  
  <pre><code>&lt;TextBox x:Name="txtUserName" Width="351" Height="45" BorderBrush="Gray" BorderThickness="2" Background="{x:Null}"/&gt;
  </code></pre>