function jan(a){
janela=window.open(a,'janela','menu=1,toolbar=no,location=no,directories=no,status=yes,menubar=no,scrollbars=yes,resizable=yes,copyhistory=no')
  }

function jan2(a){
janela=window.open(a,'janela', 'height=450,width=520,menu=1,toolbar=no,location=no,directories=no,status=yes,menubar=no,scrollbars=yes,resizable=yes,copyhistory=no,left=20,top=5')
}