左右图片循环滚动停顿一下后继续

<Script Language="JavaScript">
   var oState = 'oImg1';
   function filterImg(){
      oDiv.filters[0].Apply();
      switch(oState){
        case 'oImg1' :
          oState = 'oImg2';
          self['oImg1'].style.visibility = 'visible';
          self['oImg2'].style.visibility = 'hidden';
          self['oImg3'].style.visibility = 'hidden';
          break;
        case 'oImg2' :
          oState = 'oImg3';
          self['oImg1'].style.visibility = 'hidden';
          self['oImg2'].style.visibility = 'visible';
          self['oImg3'].style.visibility = 'hidden';
          break;
        case 'oImg3' :
          oState = 'oImg1';
          self['oImg1'].style.visibility = 'hidden';
          self['oImg2'].style.visibility = 'hidden';
          self['oImg3'].style.visibility = 'visible';
          break;
        default :
          break;
      }
      oDiv.filters[0].Play();
      setTimeout('filterImg()',1500);
   }
</Script>
<body onload="setTimeout('filterImg()',1500);">
<div id="oDiv" style="position:absolute;left:expression(document.body.clientWidth/2-50);top:expression(document.body.clientHeight/2-50);width:100px;height:100px;filter:progid:DXImageTransform.Microsoft.Slide(slideStyle='PUSH',bands=1);">
     <a href="http://www.lamking.com"><img id="oImg1" src="http://www.lamking.com/bbs/pic/headpic/7.gif" style="width:100px;height:100px;visibility:hidden;position:absolute;border:0;top:0px;left:0px;"></a>
     <a href="http://www.lamking.com"><img id="oImg2" src="http://www.lamking.com/bbs/pic/headpic/8.gif" style="width:100px;height:100px;visibility:hidden;position:absolute;border:0;top:0px;left:0px;"></a>
     <a href="http://www.lamking.com"><img id="oImg3" src="http://www.lamking.com/bbs/pic/headpic/9.gif" style="width:100px;height:100px;visibility:hidden;position:absolute;border:0;top:0px;left:0px;"></a>
</div>
</body>