function popup(urlPop,W,H,tit){
  var windowW=W; // width
  var windowH=H; // height
  var windowX = (screen.width/2)-(windowW/2);
  var windowY = (screen.height/2)-(windowH/2);
  var title =  tit; // title
  s = "width="+windowW+",height="+windowH+",left="+windowX+",top="+windowY;
  NFW=window.open(urlPop,"OandS","scrollbars=1,"+s);
}