title: uiBinder on Button Clickevent
body: <p>I'm trying to use uiBinder. I followed the tutorial provided by
  google, but I don't know why clickevent doesn't work? I want to count number of clicks and show it in the span, it doesn't work, I also put window.alert but it seems that the event handler is not called at all! Can anyone help me? It's couple of hours I'm working on it but can't find the problem!</p>
  
  <p>Thank you so much</p>
  
  <p>P.S.
  Below is my code</p>
  
  <hr>
  
  <pre><code>&lt;ui:UiBinder xmlns:ui="urn:ui:com.google.gwt.uibinder"
     xmlns:g="urn:import:com.google.gwt.user.client.ui"&gt;
     &lt;ui:style&gt;
     &lt;/ui:style&gt;
     &lt;g:HTMLPanel&gt;
      &lt;table&gt;
          &lt;tr&gt;
              &lt;td&gt;&lt;img ui:field='imgPrd'/&gt;&lt;/td&gt;
              &lt;td&gt;
                 &lt;span ui:field='lblNum'&gt;&lt;/span&gt;
                  &lt;g:Button ui:field='btnAdd'&gt;&lt;/g:Button&gt;
              &lt;/td&gt;
          &lt;/tr&gt;
      &lt;/table&gt;
     &lt;/g:HTMLPanel&gt;
  </code></pre>
  
  <p></p>
  
  <hr>
  
  <pre><code>public class uiProductList extends Composite {
  
  @UiField Button btnAdd;
  @UiField ImageElement imgPrd;
  @UiField SpanElement lblNum;
  
  int count;
  private static uiProductListUiBinder uiBinder =
  GWT.create(uiProductListUiBinder.class);
  
  interface uiProductListUiBinder extends UiBinder&lt;Widget,
  uiProductList&gt; {
  }
  
  public uiProductList() {
     initWidget(uiBinder.createAndBindUi(this));
  }
  
  
  @UiHandler("btnAdd")
  void handleClick(ClickEvent e) {
    Window.alert("test");
    count++;       
    lblNum.setInnerText(Integer.toString(count));
   }
  
  }
  </code></pre>