Forms Data Submit

my button is not working for register execute page. html code

<form>
    <h3>Let`s Get Started</h3>
    <br />
    <span id='message'></span>
    <br />
    <br />
    <label class="form-group">
        <input type="email" class="form-control" required autocomplete="off">
        <span>Your email*</span>
        <span class="border"></span>
    </label>
    <label class="form-group">
        <input id="password" name="password" type="password" class="form-control" required autocomplete="off">
        <span for="">password*</span>
        <span class="border"></span>
    </label>
    <label class="form-group">
        <input id="confirm_password" onkeyup='check()' onChange="check()" name="confirm_password" type="password" required autocomplete="off" class="form-control">

        <span for="">Confrim Password*</span>
        <span class="border"></span>
    </label>
    <input type="hidden" name="btc_register" value="">
    <input type="hidden" name="referral" value="" id="myrefnum">
    <button type="button" name="btnsub" id="BtnSignUp">Submit </button>
</form>

javascript function

$(document).on('click', '#BtnSignUp', function() {
  var email = $('#mailselect').val();
  var pass = $('#confirm_password').val();
  var RefNum = $('#myrefnum').val();

  if (email != ''&& pass != '') {
    $.ajax({
      url: "register-execute.php",
      method: "POST",
      data: {
        email: email,
        pass: pass,
        RefNum: RefNum
      },
      success: function(data) {
        $('#message').html('<div class="alert-success">' + data + '</div>');
      }
    });

    setInterval(function() {
      $('#message').html('');
    }, 5000);

  } else {
    alert("All Fields are required");
  }
});