附加区域的自动年龄计算

i am working on one registration form. in that there is a one main form and another are child forms.child form are not required.its an optional.it will opens on click add more. Following image illustrate the process of adding child form

On click addData following form would be opens

in that i am using age field. which is auto calculated on selecting date.and following is my code for main form to cal

$(document).on('change', '.dateholder1', function(e){
    var dob = new Date($(this).val());
    //var dob = e.date;
    var today = new Date();
    var age = Math.floor((today-dob) / (365.25 * 24 * 60 * 60 * 1000));
    $(".ageclass1").val(age);
});

its work fine in main form. but how can i display age on child form?

Please Check My Fiddle http://jsfiddle.net/5h1rpjqs/

The problem is here:

$(".ageclass1").val(age);

'cause we have many ".ageclass1" and browser doesn't understand which one to change and then change them all (^_^;). So we have to change that line with something like this:

$(this).next().val(age);

This is the new code

$(document).on('change', '.dateholder1', function(e){
    var dob = new Date($(this).val());
    //var dob = e.date;
    var today = new Date();
    var age = Math.floor((today-dob) / (365.25 * 24 * 60 * 60 * 1000));
    $(this).next().val(age);
});

$(".addDate").click(function(){
    $("#appenddiv").append($("#appendContent").html() + "<div class='clearfix'></div>");
});

And this is new jsfiddle: http://jsfiddle.net/5h1rpjqs/5/

$(document).on('change', '.dateholder1', function(e){
    var dob = new Date($(this).val());
    //var dob = e.date;
    var today = new Date();
    var age = Math.floor((today-dob) / (365.25 * 24 * 60 * 60 * 1000));
    $(this).next().val(age);
});

$(".addDate").click(function(){
    $("#appenddiv").append($("#appendContent").html() + "<div class='clearfix'></div>");
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<h3>This is working demo</h3><br>
<input type="text" name="date" class="dateholder1" placeholder="yyyy/mm/dd">
<input type="text" name="age" class="ageclass1" placeholder="age">
<span class='addDate'>Add</span>
<br><br>
<div id="appenddiv">

</div>

<div style="display:none" id='appendContent'>
  <input type="text" name="date" class="dateholder1" placeholder="yyyy/mm/dd">
  <input type="text" name="age" class="ageclass1" placeholder="age"><br>
  <span>How Can i Calculate age here On Change dateHolder</span>
</div>

</div>