title: get selected option before onchange
body: <p>I have a select tag like this</p>
  
  <pre><code>&lt;select class="selecttag" onchange="onchangeEvent()"&gt;
  &lt;option value="1"&gt;value1&lt;/option&gt;
  &lt;option value="2"&gt;value2&lt;/option&gt;
  &lt;option value="3"&gt;value3&lt;/option&gt;
  &lt;option value="4"&gt;value4&lt;/option&gt;
  &lt;/select&gt;
  </code></pre>
  
  <p>How can I get selected option before onchange event?</p>