title: Can't locate element using Selenium2Library due to ui-widget-overlay
body: <p>I am trying to click a button/element on a popup window using Selenium2Library in Robotframework: </p>
  
  <pre><code>Click Element   name=OK
  </code></pre>
  
  <p>But I get the following error in Robotframework:</p>
  
  <pre><code>ValueError: Element locator 'name=OK' did not match any elements.
  </code></pre>
  
  <p>I Believe this is happening due to an ui-widget-overlay that does not disappear. Below are snippets from the html code, containing the Ok button and the ui-widget-overlay:</p>
  
  <pre><code>&lt;button type="button" class="ui-button ui-widget ui-state-default ui-corner-all ui-button-text-only" role="button" aria-disabled="false"&gt;&lt;span class="ui-button-text"&gt;OK&lt;/span&gt;&lt;/button&gt;
  
  &lt;div class="ui-widget-overlay" style="width: 1793px; height: 620px; z-index: 1005;"&gt;&lt;/div&gt;
  </code></pre>
  
  <p>I know that I can successfully click element using xpath, but the xpath is dynamic in this case and I want to use a fixed value. Also, "Click Button" keyword did not work either.</p>
  
  <p>Please let me know how I can go about this.</p>