samples/mail/src/com/google/gwt/sample/mail/client/AboutDialog.ui.xml

<ui:UiBinder xmlns:ui='urn:ui:com.google.gwt.uibinder'
  xmlns:g='urn:import:com.google.gwt.user.client.ui'
  xmlns:mail='urn:import:com.google.gwt.sample.mail.client'>

  <ui:style>
  .aboutText {
    width: 24em;
    padding: 10px;
    text-align: left;
  }
  </ui:style>

  <g:DockPanel>
    <g:Dock direction='SOUTH'>
      <g:Button text='Close' ui:field='closeButton' />
    </g:Dock>
    <g:Dock direction='CENTER'>
      <g:HTML styleName='{style.aboutText}'>
        This sample application demonstrates the
        construction of a complex user interface using GWT's built-in
        widgets. Have a look at the code to see how easy it is to build
        your own apps!
      </g:HTML>
    </g:Dock>
  </g:DockPanel>

</ui:UiBinder>