function mudar(opcao) {
   if (opcao == 'pac-londres')
   {location.href='pacotes.php?chama=pac-londres';}
   
else if (opcao == 'pac-irlanda'){location.href='pacotes.php?chama=pac-irlanda';}
else if (opcao == 'pac-africa'){location.href='pacotes.php?chama=pac-africa';}
else if (opcao == 'pac-eua'){location.href='pacotes.php?chama=pac-eua';}
else if (opcao == 'pac-canada'){location.href='pacotes.php?chama=pac-canada';}
else if (opcao == 'pac-australia'){location.href='pacotes.php?chama=pac-australia';}
else if (opcao == 'pac-mes'){location.href='pacotes.php?chama=pac-mes';}

   
 /*nda*/ 
   else 
   {alert('Escolha alguma opcao');}
}