title: Set the first option value of a select using jquery
body: <p>Does anyone know how to set the first option value of a select using jquery? For example i have the following select tag.</p>
  
  <pre><code>&lt;select id = "my-id"&gt;
      &lt;option value=""&gt;&lt;/option&gt;
  &lt;/select&gt;
  </code></pre>
  
  <p>I want to set the value. So far I have unsuccessfully attempted the following.</p>
  
  <pre><code>$("select#my-id").first().val("hello world");
  
  document.getElementById('my-id').value="hello world";
  
  $("select#my-id option")
           .each(function() {
                   this.text = query.eguide;
                   this.value =query.eguide;});
  </code></pre>