How to display loading icon until pdf file is loaded?

<div id=container><img src="loading.gif" id="loadingpdf" alt="loading"
   style="display:none;margin:auto;" /><object id="pdf" data='<?php echo $pdf;?
   >#scrollbar=1'type='application/pdf' style="width:100%;height:100%;">
   </object></div>


   $("#loadingpdf").show();
      $("#pdf").hide();

       $('#pdf').load('<?php echo $pdf;?>', function() {
         $("#loadingpdf").hide();
         $("#pdf").show();
       })