title: Button how to remove border
body: <p>I have a question about dat wpf buttons.
  In my app I have fore example some code</p>
  
  <pre><code>&lt;Button x:Name="SukaKnopka" VerticalAlignment="Top" HorizontalAlignment="Right" Background="Black" MaxHeight="20" MaxWidth="20" BorderBrush="Black"&gt;
      &lt;Image Source="ButtonsImages/close_btn.png" Stretch="Fill"/&gt;
  &lt;/Button&gt;
  </code></pre>
  
  <p>All is fine but there is some little border around this button =( I have tryed <code>BorderBrush="{x:Null}"</code>
  but the border again present. (This border highlights if MouseOver)</p>