Javascript popups and IE woes

1

I’ve got this expression for popups in my flash animation:

renderButton.onRelease = function() {
    getURL("javascript:popUpWindow('renderings.html', 10, 10, 670, 495);");
};

and this javascript in my HTML doc:

<script language="JavaScript">
var popUpWin=0;
function popUpWindow(URLStr, left, top, width, height)
{
  if(popUpWin)
  {
    if(!popUpWin.closed) popUpWin.close();
  }
  popUpWin = open(URLStr, 'popUpWin', 'toolbar=no,location=no,directories=no,status=no,menub ar=no,scrollbar=no,resizable=no,copyhistory=yes,width='+width+',height='+height+',left='+left+', top='+top+',screenX='+left+',screenY='+top+'');
}
</script>

This works super in everything but PC Internet Explorer. Sometimes in IE it will just put “javascript:popUpWindow(‘renderings.html’, 10, 10, 670, 495);” in the browser URL bar and nothign will happen. What could be causing this? Is there anything I can tweak in my AS or JS to alleviate this problem?

Thanks!