<form id="form1" target="_blank" method="POST" action="../page1">
<input type="radio" name="paymentType" value="PC">
<input type="radio" name="paymentType" value="AC">
<input type="radio" name="paymentType" value="MC">
<button type="submit" name="pay">Отправить</button>
</form><script type="text/javascript">
$('#form1 input').on('change', function() {
console.log($('input[name=radioName]:checked', '#myForm').val()); // выводим в консоль выбранное значение
switch ($('input[name=radioName]:checked', '#myForm').val()) {
case 'PC':
$("#form1").attr("action", '../page/sds/3');
break;
case 'AC':
$("#form1").attr("action", '../page/sds/2');
break;
case 'MC':
$("#form1").attr("action", '../page/3');
break;
}
});
</script>
В чем проблема попробовать?