title: how to dropdown option keep selected after page loads onchange
body: <p>how i can get dropdown option keep selected after loading a page with function onchange? currently i can just load the page according to selected value from my dropdown. and after loading page it's selected with first value be default.</p>
  
  <pre><code>&lt;select id="extDropDown"&gt;
          &lt;option&gt;Select Extension&lt;/option&gt;
          &lt;option value="*"&gt;All&lt;/option&gt;
          &lt;option value="zip"&gt;ZIP&lt;/option&gt;
          &lt;option value="rar"&gt;RAR&lt;/option&gt;
          &lt;option value="php"&gt;PHP&lt;/option&gt;
          &lt;option value="html"&gt;HTML&lt;/option&gt;
          &lt;option value="htm"&gt;HTM&lt;/option&gt;
          &lt;option value="jpg"&gt;JPG&lt;/option&gt;
          &lt;option value="bmp"&gt;BMP&lt;/option&gt;
          &lt;option value="txt"&gt;TEXT&lt;/option&gt;
          &lt;option value="docs"&gt;DOCS&lt;/option&gt;
          &lt;option value="xlsx"&gt;XLSX&lt;/option&gt;
          &lt;option value="xls"&gt;XLS&lt;/option&gt;
      &lt;/select&gt;
  
  
  $( document ).ready(function() {
      $( '#extDropDown' ).bind( 'change', function( e ){
      document.location.href = "?dir=&lt;?php echo $dir; ?&gt;&amp;action=loadfiles&amp;ftype=" + $( this ).val();
    });
  }); 
  </code></pre>