title: Can't click a button on a pop-up in Selenium IDE
body: <p>I am trying to click a button on a pop-up which is opened from another pop up in Selenium IDE. I have no problem running commands in the second pop i.e. I can search for and select awards however when I try to click the Add button nothing happens. If the step is recorded in IDE the following commands are displayed:</p>
  
  <pre><code>&lt;tr&gt;
      &lt;td&gt;click&lt;/td&gt;
      &lt;td&gt;//button[@type='button']&lt;/td&gt;
      &lt;td&gt;&lt;/td&gt;
  &lt;/tr&gt;
  &lt;tr&gt;
      &lt;td&gt;click&lt;/td&gt;
      &lt;td&gt;id=ctl00_PlaceHolderMain_New_pickerComponents_ButtonAddToTableResults&lt;/td&gt;
      &lt;td&gt;&lt;/td&gt;
  &lt;/tr&gt;
  </code></pre>
  
  <p>but this doesn't work. I have also tried:</p>
  
  <pre><code> &lt;tr&gt;
      &lt;td&gt;click&lt;/td&gt;
      &lt;td&gt;xpath=//span[text()='Add']&lt;/td&gt;
      &lt;td&gt;&lt;/td&gt;
  &lt;/tr&gt;
  </code></pre>
  
  <p>This is the HTML: </p>
  
  <pre><code>&lt;div class="ui-dialog-buttonpane ui-widget-content ui-helper-clearfix"&gt;
  &lt;div class="ui-dialog-buttonset"&gt;
  &lt;button class="ui-button ui-widget ui-state-default ui-corner-all ui-button-text-only" type="button" role="button" aria-disabled="false"&gt;
  **&lt;span class="ui-button-text"&gt;Add&lt;/span&gt;**
  &lt;/button&gt;
  &lt;button class="ui-button ui-widget ui-state-default ui-corner-all ui-button-text-only" type="button" role="button" aria-disabled="false"&gt;
  &lt;span class="ui-button-text"&gt;Cancel&lt;/span&gt;
  &lt;/button&gt;
  &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>but no joy. I'm not sure why I can use other commands in this pop-up and not be able to click the add button.</p>