title: JQuery - Remove all option from Selectbox except for first and selected
body: <p>I have a html select box with several options. Upon selection of an option I want Only the selected option and the first option to be shown in the select option dropdown. I know how to filter and show only one option but I cannot figure out how to include both option where the 'selected' option remains 'selected'. I have include snippets similar to of my code as well as a demo.<p>HTML:</p>
  
  <pre><code>&lt;select id="myDropdown"&gt;
  &lt;option selected&gt;Select fruit&lt;/option&gt;
  &lt;option&gt;Grapes&lt;/option&gt;
  &lt;option&gt;Bananas&lt;/option&gt;
  &lt;option&gt;Oranges&lt;/option&gt;
  &lt;option&gt;Apples&lt;/option&gt;
  &lt;/select&gt;
  </code></pre>
  
  <p>JS:</p>
  
  <pre><code>$(document).on('change', '#myDropdown', function() {
      $('option', this).not(this,'option:gt(0)').siblings().remove(); });
  </code></pre>
  
  <p>I am trying to use the first option to perform another function 'on change' so I need the selected option to remain selected while the rest being filtered out except for the first. For example if 'Oranges' were selected, this is what you would see:</p>
  
  <pre><code>&lt;select id="myDropdown"&gt;
       &lt;option&gt;Select fruit&lt;/option&gt;
       &lt;option&gt;Oranges&lt;/option&gt;  //selcted value
  &lt;/select&gt;
  </code></pre>
  
  <p>BTW I am using jquery mobile to style as well.</p>
  
  <p><a href="http://jsfiddle.net/znx9hxvu/8/" rel="noreferrer">jsfiddle</a></p>