var subwin=null;
function openwin(url,l,t,w,h)
{
  if ((navigator.appName.indexOf("Explorer") >= 0) && (navigator.platform.indexOf("Win") >= 0))
  {
    if ((subwin!=null)&&(!subwin.closed)) subwin.close();subwin=window.open(url,"subwindow","left="+l+",top="+t+",width="+w+",height="+h+",resizable=1,scrollbars=0");
  }
}