var wndw=0;
function openWindow(url,width,height) {
  height=height;
  x = (640 - width)/2, y = (480 - height)/2;
  if (screen) {
    y = (screen.availHeight - height)/2;
    x = (screen.availWidth - width)/2;
  }
  if (screen.availWidth > 1800) {
    x = ((screen.availWidth/2) - width)/2;
  }
  if(wndw) if(!wndw.closed) wndw.close();
  wndw=window.open(url,'video','copyhistory=no,width='+width+',height='+height+'innerHeight='+height+',innerWidth='+width+',screenX='+x+',screenY='+y+',top='+y+',left='+x);

}