var popUpWin

function makePopUpWin(varfilename)
 {
  var vflnm = "dynamic_window.php?filename=" + eval("varfilename")

  if (!popUpWin || popUpWin.closed) 
  {
   popUpWin = eval("window.open(vflnm,'',config='top=20,left=20,height=550,width=794,toolbar=no,menubar=no,scrollbars=yes,resizable=yes,location=no,directories=no,status=no')")
   if (!popUpWin.opener) 
   {
    popUpWin.opener = window
   }

  } else 
  {
   popUpWin.focus()
  }
}

function closePopUpWin() {
 if (popUpWin && !popUpWin.closed)
  popUpWin.close();
}