<link href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/js/bootstrap.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<!------ Include the above in your HEAD tag ---------->
<div class="container">
<div class="row">
<div class='element' id='div_1'>
<div class="col-md-12">
<div class="form-group">
<div class="input-group">
<input type='text' placeholder='Enter your skill' id='txt_1' class="form-control">
<span class='btn btn-primary add input-group-addon'>Add Skill</span>
</div>
</div>
</div>
</div>
</div>
</div>
$(document).ready(function(){
// Add new element
$(".add").click(function(){
// Finding total number of elements added
var total_element = $(".element").length;
// last <div> with element class id
var lastid = $(".element:last").attr("id");
var split_id = lastid.split("_");
var nextindex = Number(split_id[1]) + 1;
var max = 1000;
// Check total number elements
if(total_element < max ){
// Adding new div container after last occurance of element class
$(".element:last").after("<div class='element' id='div_"+ nextindex +"'></div>");
// Adding element to <div>
$("#div_" + nextindex).append(" <div class='col-md-6'> <div class='row'><div class='form-group'> <div class='input-group'><input type='text' class='form-control' placeholder='Enter your skill' id='txt_"+ nextindex +"'><span id='remove_" + nextindex + "' class='input-group-addon remove btn btn-danger'>X</span></div></div></div></div>");
}
});
// Remove element
$('.container').on('click','.remove',function(){
var id = this.id;
var split_id = id.split("_");
var deleteindex = split_id[1];
// Remove <div> with id
$("#div_" + deleteindex).remove();
});
});