How to send array in jquery to controller?

[eluser]T I[/eluser]
It shd work.

Code:

$('#submit').click(function() {

        var jname = $('#name').val();
        var jprincipal = $('#principal').val();
        var jpayment = $('#monthly_payment').val();
        var jrate = $('#interest_rate').val();

        $.getJSON("<?= site_url('debt_sw/save') ?>", {debt_name: jname,principal:jprincipal,monthly:jpayment,interest_rate:jrate}, function(data) {

          if(data)
              {
                   $("#update").html(data);
                 $("tr:even").css("background-color", "#7FDDF6");
                 $("tr:odd").css("background-color", "#ECECEC");

              }

        });
    });
});