title: Get select option by value using javascript
body: <p>I have selection menu:</p>
  
  <pre><code>&lt;div class="selector"&gt;
  &lt;select&gt;
  &lt;option value="valueA"&gt;Value A&lt;/option&gt;
  &lt;option value="valueB"&gt;Value B&lt;/option&gt;
  &lt;option value="valueC"&gt;Value C&lt;/option&gt;
  &lt;/select&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>and I need Javascript (no jquery!) to get option by value and change it's text (innerHtml)</p>
  
  <p>for example when I run the function I need to get option with the value "valueB" from class "selector" and change it's text to Value Whatever.</p>