title: Why am i using UpdateSourceTrigger=PropertyChanged ,TwoWay is not enough?
body: <p>hi; there are Source and target textbox txttarget has a binding to txtsource. when writing something in txtsource, txttarget is changed.Everything is good. But writing on txttarget, i dont see any changes at txttarget? there is TwoWay mode. Twoway mode is not enough? can i write without using "UpdateSourceTrigger=PropertyChanged"?</p>
  
  <pre><code>
     &#60;Grid&#62;
          &#60;TextBox Height="23" HorizontalAlignment="Left" Margin="155,62,0,0" Name="txtSource" VerticalAlignment="Top" Width="120" /&#62;
          &#60;TextBox Height="23" HorizontalAlignment="Left"
                   Text="{Binding ElementName=txtSource,Path=Text,Mode=TwoWay}" 
                   Margin="155,113,0,0" Name="txtTarget" VerticalAlignment="Top" Width="120" /&#62;
      &#60;/Grid&#62;
  </code></pre>