title: Add class "active" to span with JQuery or JavaScript
body: <p>I have three spans</p>
  
  <pre><code>$(".regions_list li span")
  [
  &lt;span&gt;​text0&lt;/span&gt;​
  , 
  &lt;span&gt;text1​&lt;/span&gt;​
  , 
  &lt;span&gt;​text2&lt;/span&gt;​
  ]
  </code></pre>
  
  <p>I want to add active class for span that text equal with <code>myVariable</code></p>
  
  <pre><code>  myVariable = "text2";
    $(".regions_list li span").eq(myVariable).addClass("active");
  </code></pre>
  
  <p>but this method doens't work for this example.</p>
  
  <p>some proposal?</p>