title: Python Selenium UnexpectedAlertPresentException
body: <p>I am running basic CRUD tests with python and lettuce using selenium webdriver.</p>
  
  <p>All of my other tests run fine, but when I click "Delete", there is a modal dialog which asks the user to confirm that they want to delete that user. The moment the popup appears, I get the exception below. I have wasted 2 hours trying to get this to work. I would imagine there is a simple fix. </p>
  
  <pre><code> File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/errorhandler.py", line 164, in check_response
      raise exception_class(message, screen, stacktrace)
  UnexpectedAlertPresentException: Message: u'Modal dialog present' ; Stacktrace: 
      at nsCommandProcessor.prototype.execute (file:///tmp/tmpeV2K89/extensions/fxdriver@googlecode.com/components/command_processor.js:11520:13)
  </code></pre>
  
  <p>The line in steps.py that is throwing the error is this.</p>
  
  <pre><code>  world.browser.find_element_by_link_text("Delete User").click()
  </code></pre>
  
  <p>And the html for that element is this.</p>
  
  <pre><code>&lt;a href="/users/5910974510923776/delete" onclick="return confirm('Are you sure you want to delete this user?');"&gt;Delete User&lt;/a&gt;
  </code></pre>