getJSON not returning data

This issue relates to when using the getJSON query in the following way;

$.getJSON('../api/get_messages_record_details2.gen.php',

{
    id: id, table: tbl
}

, function (data)
{
    console.log(data);
    if (data)
    {
        console.log("we got data");
        if (data.items[0].error == 'OK')
        {
            $("#id").val(data.items[0].id);
            $("#message_no").val(50);
            $("#status_value").val(data.items[0].status_value);
            $("#date_created").val(data.items[0].doe);
            $("#xml_data").val(data.items[0].xml_data);
        } else
        {
            $("#messages").attr('class', 'btn-danger');
            $("#messages").html("ERROR: " + data.return.error);

        }
    }

});

It was noted that the console.log(data) was not working, however when using browser developer tools, the target url was returning results as expected.

I had been using echo(...) in the target url an while this allowed the target url to be opened directly, it would not work in the context as above. 

So by all means use echo(...) in the target url, for example; 

echo $_REQUEST['id'];

which allows it to be seen when the target url is run directly, but it must be commented out when called from the main page.