<button type="button" class="btn btn-block btn-primary" data-toggle="modal" data-target="#dataModal"></button>

<!-- Modal -->
<div class="modal fade" id="dataModal" tabindex="-1" role="dialog" aria-labelledby="exampleModalLabel" aria-hidden="true">
  <div class="modal-dialog modal-lg" role="document">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title" >Adicionar dados</h5>
        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
          <span aria-hidden="true">×</span>
        </button>
      </div>

      <div class="modal-body">

<form id="usersform" method="post">
     <input type="text" name="nome" id="nome"/>
       <input type="email" name="email" id="email"/>
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-secondary" data-dismiss="modal">CANCELAR</button>
        <button type="submit" class="btn btn-success" id="submit" >ADD USER</button>
</form>
      </div>
    </div>
  </div>
</div>

<script>

$(document).on('submit', '#usersform', function(event){
        event.preventDefault();
    $.ajax({
                url:"insert.php",
                method:'POST',
                data:new FormData(this),
                contentType:false,
                processData:false,
                success:function(data){
                    alert("Cadastro realizado com sucesso!");
                    $("#usersform")[0].reset();
                    $("#dataModal").modal('hide');

                }
});
});

</script>

<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "system";

// Create connection
$conn = mysqli_connect($servername, $username, $password, $dbname);
// Check connection
if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}
$nome = $_POST['nome'];
$email = $_POST['email'];
$sql = "INSERT INTO users (nome,email)
VALUES ('$nome', '$email')";

if (mysqli_query($conn, $sql)) {
    echo "New record created successfully";
} else {
    echo "Error: " . $sql . "<br>" . mysqli_error($conn);
}

mysqli_close($conn);

?>

$("#dataModal").modal('hide');

$("#dataModal").hide();