ABN Number Validation using Java Script with Formula Explaination

1.)Source Code Part 1 Html abn number validation

<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/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 ---------->
<script src="http://ajax.aspnetcdn.com/ajax/jquery.validate/1.9/jquery.validate.js"></script>
<div class="container">
 <div class="row">
   
         <div>
   <form  id="register_form" class="forms-sample" method="post" action="register" enctype="multipart/form-data">
   <div class="form-group">
                          <label >ABN Number</label>
                           <input id="contact_abn_no" type="text" name="abn_no"  class="form-control" value="" placeholder="ABN Number">
        
         
                           <span class="text-danger" style="font-size:12px;display:none;">{{ $errors->first('abn_no') }}</span>
          
            </div>
            <br/>
                        <div>
                        <button style="margin-top:0px;" type="submit" class="btn btn-primary btn-lg btn-block btn-block_top_margin btnsubload">Submit</button>
                        </div>
          
          
           </form>  
           </div>
          

  
 </div>
</div>

2.)Source Code Part 2 Javascript abn number validation

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery.mask/1.14.10/jquery.mask.js"></script>
   
    <script type="text/javascript">

$.ajaxSetup({

    headers: {

        'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')

    }

});

$(function() {
            $("#contact_abn_no").mask("00 000 000 000", {
    onChange: function () {
        console.log($('#contact_abn_no').val());
    }
});
        });




$(function(){
    $("#register_form").validate({ 
    rules: {
       

        "abn_no":  { 
            checkAbn : true,
            required: true

        }


        
    }, 
    messages: {
       
        "abn_no": {
        required: "Please Enter ABN Number" 
        }
       
    },
    highlight: function (element, errorClass, validClass) { 

   $("#loading").css("visibility", "hidden"); 
    return false;
    $("#loading").css("visibility", "visible");
    },
    errorElement: 'span',
    submitHandler: function (form) {
    form.submit();
    }
    });



$.validator.addMethod("checkAbn", function(value, element) {


    var abn_val = $("#contact_abn_no").val()
    if (abn_val.trim() != '') {
                    var weights = [10, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19];
                    if (abn_val.length == 14) {
                        //remove spaces from string
                        abn_val = abn_val.replace(/\s+/g, '');
                        // strip anything other than digits
                        abn_val = abn_val.replace("/[^\d]/", "");
                        // check length is 11 digits
                        if (abn_val.length == 11) {
                            // apply ato check method 
                            var sum = 0;
                            for (var i = 0; i < 11; i++) {
                                var digit = abn_val[i] - (i ? 0 : 1);
                                var sum = sum + (weights[i] * digit);
                            }
                            return ((sum % 89) == 0);
                        } else {
                            return false;
                        }
                    }
                } else {
                    return true;
                }

  // return true;
}, "ABN number not vailid.");

})


</script>