var XWin = null;
Count = 0;
var Name = "XWin";
var Rand = Math.round(Math.random() * 100);

function openXWin(URL, Width, Height){
  Name = "XWin" + Rand + Count++;
  closeXWin();
  XWin = window.open(URL, Name, "width=" + Width + ",height=" + Height +",scrollbars");
  XWin.focus();
}

function closeXWin(){   
  if(XWin != null) 
    if(!XWin.closed) 
      XWin.close();
}