register.php

<?php
  error_reporting(0);
  $this->load->library('form_validation');
  echo form_open('register'); ?>
  <div class="login register container">
    <img class="icon reg" src="<?php echo base_url("img/twitter.png")?>" alt="Twitter">
    <h1>Register</h1>
    <div class="form-group">
        <label for="firstname">First Name</label>
        <input class="form-control" type="text" name="firstname" value="<?php echo set_value('firstname'); ?>"/>
        <?php echo form_error('firstname'); ?>
    </div>
    <div class="form-group">
        <label for="lastname">Last Name</label>
        <input class="form-control" type="text" name="lastname" value="<?php echo set_value('lastname'); ?>"/>
        <?php echo form_error('lastname'); ?>
    </div>
    <div class="form-group">
        <label for="email">Email</label>
        <input class="form-control" type="email" name="email" value="<?php echo set_value('email'); ?>"/>
        <?php echo form_error('email'); ?>
    </div>
    <div class="form-group">
        <label for="location">Location</label>
        <input class="form-control" type="text" name="location" value="<?php echo set_value('location'); ?>"/>
        <?php echo form_error('location'); ?>
    </div>
    <div class="form-group">
        <label for="username">Username</label>
        <input class="form-control" type="text" name="username" value="<?php echo set_value('username'); ?>"/>
        <?php echo form_error('username'); ?>
    </div>
    <div class="form-group">
        <label for="password">Password</label>
        <input class="form-control" type="password" name="password" value="<?php echo set_value('password'); ?>"/>
        <?php echo form_error('password'); ?>
    </div>
    <button type="submit" class="btn btn-primary">Sign Up</button>
  </form>
  </div>

  <script type="text/javascript" src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
</body>
</html>