How to remove, validate adding dynamic form element and add to MySQL database using jQuery AJAX?

So, i found my solution on how to dynamically add form element using jQuery and i implement it, and it works so smoothly. By the way, i made a GIS web app to provide precise resident location and information of a place. And i stuck on how to manipulate the adding of resident's information together with its members to the database.

My initial code:

JS

 $(document).ready(function() {
 $('#addRow').click(function() {
 $('<div/>', {
   'class': 'extraPerson',
   html: GetHtml()
 }).hide().appendTo('#container').slideDown('slow');
 });

 $(document).on('click', "#removeRow", function() {
 var len = $('.extraPerson').length;
 if (len <= -1) {
   $('.extraPerson [name=firstname]').slideUp('slow');
   $('.extraPerson [name=lastname]').slideUp('slow');
   $('.extraPerson [name=gender]').slideUp('slow');
   $(this).fadeOut('slow');
 } else {
   $('.extraPerson [name=firstname' + (len - 1) + ']').slideUp('slow');
   $('.extraPerson [name=lastname' + (len - 1) + ']').slideUp('slow');
   $('.extraPerson [name=gender' + (len - 1) + ']').slideUp('slow');
   $(this).fadeOut('slow');
 }
 });
 });

 function GetHtml() {
 var len = $('.extraPerson').length;
 var $html = $('.extraPersonTemplate').clone();
 $html.find('[name=firstname]')[0].name = "firstname" + len;
 $html.find('[name=lastname]')[0].name = "lastname" + len;
 $html.find('[name=gender]')[0].name = "gender" + len;
 return $html.html();
 }

HTML

<div class="extraPersonTemplate">
  <div class="controls controls-row">
    <input class="span3" placeholder="First Name" type="text" name="firstname">
    <input class="span3" placeholder="Last Name" type="text" name="lastname">
    <select class="span2" name="gender">
        <option value="Male">Male</option>
        <option value="Female">Female</option>
    </select>
    <a href="#" id="removeRow"><i class="icon-plus-sign icon-white"></i> Remove Row </a>
    </div>
</div>
<div id="container"></div>
<a href="#" id="addRow"><i class="icon-plus-sign icon-white"></i> Add another     family member</a>

CSS

.extraPersonTemplate {
  display: none;
}

Now, how do i validate the members if a user forgot to enter a value of a member even he/she clicked the add row or one of its inputs are null in jQuery???

And if i submit the form, how to add those inputted members to my MySQL database?

Any help, suggestions and ideas would be heavenly appreciated.

JSFiddle to the code above^