Untitled

<link rel="stylesheet" href="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.2/jquery.min.js"></script>
  <script src="http://ajax.aspnetcdn.com/ajax/jquery.validate/1.9/jquery.validate.min.js"></script>
  <script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
  <script type="text/javascript" src="assets/js/signup.js"></script>
  <script type="text/javascript" src="assets/js/showMessage.js"></script>
</head>
<body>
  <div class="container">
    <div class="row" id="pwd-container">
      <div id="messages"></div>
      <div class="col-md-4"></div>
      <div class="col-md-4">
        <section class="myform">
          <form method="post" role="form" id="signup-form">
            <h1>Registration</h1>
            <div class="form-group has-feedback">
              <input type="text" name="username" id="username" class="form-control input-lg" placeholder="Username" />
              <span class="glyphicon form-control-feedback" id="username1"></span>
            </div>
            <div class="form-group has-feedback">
              <input type="email" name="email" placeholder="Email" class="form-control input-lg" id="email"/>
              <span class="glyphicon form-control-feedback" id="email1"></span>
            </div>
            <div class="form-group has-feedback">
              <input type="password" name="password" id="password" class="form-control input-lg" placeholder="Password" />
              <span class="glyphicon form-control-feedback" id="password1"></span>
            </div>
            <div class="form-group has-feedback">
              <input type="password" class="form-control input-lg" name="password_confirm" id="password_confirm" placeholder="Confirm password" />
              <span class="glyphicon form-control-feedback" id="password_confirm1"></span>
            </div>
            <button type="submit" class="btn btn-lg btn-primary btn-block" name="btn-signup" id="btn-signup">Sign up</button>
            <span>Already have an account? <a href="index.php">Go back</a></span>
          </form>
        </section>
      </div>
    </div>
  </div>
</body>

$.getScript('showMessage.js');
$('document').ready(function()
{
  $('#signup-form').validate({
    rules: {
      username: {
        minlength: 3,
        required: true
      },
      password: {
        minlength: 3,
        required: true
      },
      email: {
        required: true,
        email: true
      },
      password_confirm: {
        required: true,
        equalTo: password,
      },
    },
    messages: {
      password: {
        required: "Please enter your password",
        minlength: "Password must be 3 characters long"
      },
      password_confirm: {
        required: "Please confirm your password",
        equalTo: "Password does not match",
      },
      username: {
        required: "Please enter your username",
        minlength: "Username must be 3 characters long"
      },
      email: {
        required: "Please enter your email",
        email: "Please enter a valid email"
      },
    },
    highlight: function(element) {
      var id_attr = "#" + $( element ).attr("id") + "1";
      $(element).closest('.form-group').removeClass('has-success').addClass('has-error');
      $(id_attr).removeClass('glyphicon-ok').addClass('glyphicon-remove');
    },
    unhighlight: function(element) {
      var id_attr = "#" + $( element ).attr("id") + "1";
      $(element).closest('.form-group').removeClass('has-error').addClass('has-success');
      $(id_attr).removeClass('glyphicon-remove').addClass('glyphicon-ok');
    },
    errorElement: 'span',
    errorClass: 'help-block',
    errorPlacement: function(error, element) {
      if(element.length) {
        error.insertAfter(element);
        element.css('margin-bottom','5px');
      } else {
        error.insertAfter(element);
        element.css('margin-bottom','16px');
      }
    },
    submitHandler: function(form){
      var data = $("#signup-form").serialize();
      alert(data);
      $.ajax({
        type : 'POST',
        url  : 'signupHandler.php',
        data : data,
        success : function(response)
        {
          if(response=="ok"){
            showMyMessage('You have successfully been logged in! Redirecting in 2 seconds...','success');
            setTimeout('window.location.href = "home.php"; ',2000);
            alert('ok tu');
          }
          else {
            showMyMessage('Something wrong! '+response,'error');
            alert('jsu tu');
          }
          return false;
        }
      });

    }
  });

<?php
require("functions.php");
session_start();
if ($_SERVER['REQUEST_METHOD'] == 'POST'){
  $db = getDb();
  //validate($_POST['user'], $db);

  $passwordHash = sha1($_POST['password']);
  $_POST['password'] = $passwordHash;
  $array = array(
    "username" => $_POST['username'],
    "email" => $_POST['email'],
    "password" => $passwordHash
);
  $query = getInsertQuery("users", $array);
  var_dump($query);
  if (mysqli_query($db, $query)) {
    echo 'ok';
    $_SESSION['username'] = $_POST['username'];
  } else {
      echo 'Unfortunately your sign up has not been successful. Please ensure you have completed all the mandatory fields.';
      echo mysqli_error($db);
  }
}