[Scantraxx]

laimas,
пока без Ajax

<script>
    var $myForm=$("#myForm");

    $(".plus").off("click").on("click",function(){
        $(".details").append('<div class="details-part"><input class="details_name" type="text" /><input class="details_value" type="text" /></div>')
});

    $("#save-form").off("click").on("click",function(){
        var detailList=[];
        $myForm.find(".details-part").each(function(){
            detailList.push({
                details_value:$(this).find(".details_value").val(),
                details_name:$(this).find(".details_name").val()
            })
        });
        $myForm.find('[name="details"]').val(JSON.stringify(detailList))
        $myForm.submit()
    });
</script>