{% macro button(text, url, classes='') %}
<table class="button{% if classes %} {{classes}}{% endif %}">
  <tbody>
    <tr>
      <td>
        <table>
          <tbody>
            <tr>
              <td><a href="{{url | safe}}">{{text}}</a></td>
            </tr>
          </tbody>
        </table>
      </td>
    </tr>
  </tbody>
</table>
{% endmacro button %}

{% macro spacer(height=16) %}
<table class="spacer">
    <tbody>
      <tr>
        <td height="{{height}}" style="font-size:{{height}}px;line-height:{{height}}px;">&nbsp;</td>
      </tr>
    </tbody>
  </table>
{% endmacro spacer %}