var lp;

function openpopup(tipname, wndheight, wndwidth) {
  if (wndheight == null) {
    wndheight='250';
  }
  if (wndwidth == null) {
    wndwidth='390';
  }

  lp = screen.width - wndwidth - 10;
  window.open(tipname + '.html', 'Tip', 'left='+lp+',top=20,width=' + wndwidth + ',height=' + wndheight +',status=0,location=0,scrollbars=no');
}