function popupImage(url,width,height) {
  var left = parseInt((screen.availWidth/2) - (width/2));
  var top = parseInt((screen.availHeight/2) - (height/2));
  var windowFeatures = "width=" + width + ",height=" + height + ",resizable,left="+left+",top="+top+",screenX="+left+",screenY="+top;
  window.open(url,"subWind",windowFeatures);
}