title: HtmlUnit onclick execution download file
body: <p>So here's the deal:<br>
  I am accessing some webpage(using HtmlUnit) on which there's a button. I programatically click that button(big thanks to Mads Hansen)</p>
  
  <pre><code>List l = page.getByXPath( "//input[@type='submit' and @value='Save as XML']" );
  ((HtmlSubmitInput)l.get(0)).click();
  </code></pre>
  
  <p>The button has an onclick event, following:</p>
  
  <pre><code>onclick="document.forms[0].action=&amp;quot;calcSaveXML_BG#POS&amp;quot;;document.forms[0].submit()"
  </code></pre>
  
  <p>When I click that button normally through the browser, I am given the chance to save a xml file on my hard drive.<br>
  The thing is, I want to be able to get that xml file programatically. Can this be done?</p>