Java Script code not running well on ie9

I have this code it suppose to display an ad for 10 seconds then load a embed code.
the thing is that it's working fine on firefox but not ie 9 it's run the ad and the embed code in the same time in the background.
Is there is anyway to resolve this problem.
the code is attached.
thank you

<script type="text/javascript">
 var nbsec=10;
 var c=0;
 var t;
 var timer_is_on=0;
 var sum=0;
 function timedCount()
 {
 c=c+1;
 t=setTimeout("timedCount()",1000);
 sum=nbsec-c;
 document.getElementById('chrono').innerHTML="<br>Loading .. Please wait "+sum+"secondes";
 if(c == nbsec){
 stopCount();
 document.getElementById('mypub').style.visibility = 'hidden';
 document.getElementById('mygame').style.visibility = 'visible';
 document.getElementById('mygame').style.display ='block';
 document.getElementById('mygame').style.height = 'auto';
 document.getElementById('mypub').style.height = '0px';
 document.getElementById('mypub').style.padding = '0px';
 document.getElementById('mypub').innerHTML="";
 }
 }
 function stopCount()
 {
 clearTimeout(t);
 timer_is_on=0;
 }
 </script>
 
 <table border ="2" align="center" color="F2FC7E"><tr><td>
 <div id="mypub"  style="visibility: visible; text-align:center; padding:20px;"> 
 
 <script>
 ..............
 </script>
 
 <div id="chrono" style="color:#FFF;"></div>
 </div>
 <div id="mygame" style="visibility: hidden;display:none; height:0px">
 <param name="initial_focus" value="true">
 <applet>
 ........................
 </applet>   
 </div>
 </td></tr></table>
 </div>
 <script type="text/javascript">
 timedCount();
 </script>
 

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