title: How to set default value for HTML select?
body: <p>I have a HTML select like this:  </p>
  
  <pre><code>&lt;select&gt;
      &lt;option&gt;a&lt;/option&gt;
      &lt;option&gt;b&lt;/option&gt;
      &lt;option&gt;c&lt;/option&gt;
  &lt;/select&gt;
  </code></pre>
  
  <p>and I have a variable named <code>temp</code> in my JavaScript:  </p>
  
  <pre><code>var temp = "a";
  </code></pre>
  
  <p>Now I want to set the value of the option that is equal to temp as default value for my select.</p>
  
  <p>How can I do it?</p>