i'm using bootstrap's form validation to validate a form. i wan to add an extra field called discount code. this field should accept only specified codes. when the field is empty it should light green, when the code is right it should light green and when the code is wrong it should light red. how can i do that using the bootstrap form validation?

thats how my form almost looks like

<form class="needs-validation" novalidate>
   <div class="form-group">
      <div class="col-md-12">
       <strong>Enter your name </strong>
       <input type="text" name="name" id="name" class="form-control" value="" required minlength="3" />
       <div class="invalid-feedback">
           Name should be at least 3 characters
       </div>
     </div>
    </div>

  <div class="col-12">
    <button class="btn btn-primary" type="submit">Submit form</button>
  </div>
</form>
<script>
(function () {
  'use strict'

  // Fetch all the forms we want to apply custom Bootstrap validation styles to
  var forms = document.querySelectorAll('.needs-validation')

  // Loop over them and prevent submission
  Array.prototype.slice.call(forms)
    .forEach(function (form) {
      form.addEventListener('submit', function (event) {
        if (!form.checkValidity()) {
          event.preventDefault()
          event.stopPropagation()
        }

        form.classList.add('was-validated')
      }, false)
    })
})()
</script>