title: Selenium IDE - How to check that an element is (CSS) visible?
body: <p>Example 1: Checking that a Twitter Bootstrap modal has opened.</p>
  
  <p>The modal already exists on the page but is hidden with CSS until the modal is opened.  So how do I verify that the modal actually opened?</p>
  
  <p>Example 2: Checking that a user error message div was displayed.</p>
  
  <p>The error message div always exists but is hidden with CSS until it is needed.  How do I verify that the message is visible?</p>