function pop_win(strurl, strname, strwidth, strheight, strscroll)
{
  var nwidth = strwidth;
  var nheight = strheight;
  var leftsize = 0;
  var topsize = 0;
  if (nwidth == 0 || nheight == 0)
  {
    nwidth = screen.width - 8;
    nheight = screen.height - 55;
  }
  else
  {
    leftsize = (screen.width) ? (screen.width - nwidth)/2 : 0;
    topsize = (screen.height) ? (screen.height - nheight)/2 : 0;
  }
  window.open(strurl, strname, 'width=' + nwidth + ',height=' + nheight + ',left=' + leftsize + ',top=' + topsize + ',toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=' + strscroll + ',resizable=no' );
}