form error

<?php
            if ($_POST) {
              print_r($_POST['photo']); //variable photo kosong
              if (!$_POST['email']) {
                echo '<p><div class="alert alert-danger">Email tidak boleh kosong!<a class="close" data-dismiss="alert" href="#">x</a></div></p>';
              } else if (!$_POST['username']) {
                echo '<p><div class="alert alert-danger">Username tidak boleh kosong!<a class="close" data-dismiss="alert" href="#">x</a></div></p>';
              } else if (!$_POST['name']) {
                echo '<p><div class="alert alert-danger">Nama tidak boleh kosong!<a class="close" data-dismiss="alert" href="#">x</a></div></p>';
              } else if (!$_POST['photo']) {
                echo '<p><div class="alert alert-danger">Photo tidak boleh kosong!<a class="close" data-dismiss="alert" href="#">x</a></div></p>';
              } else if (!$_POST['password']) {
                echo '<p><div class="alert alert-danger">Password tidak boleh kosong!<a class="close" data-dismiss="alert" href="#">x</a></div></p>';
              } else if (!$_POST['level']) {
                echo '<p><div class="alert alert-danger">Level tidak boleh kosong!<a class="close" data-dismiss="alert" href="#">x</a></div></p>';
              } else {
                // buat prepared statements
                $stmt = mysqli_prepare($db, "INSERT INTO user (`email`, `username`, `password`, `name`, `photo`, `level`)
                VALUES (?, ?, ?, ?, ?, ?)");

                // hubungkan "data" dengan prepared statements
                mysqli_stmt_bind_param($stmt, "ssssss",
                $email, $username, $name, $photo, $password, $level);

                // filter data yang diinputkan
                $email = filter_input(INPUT_POST, 'email', FILTER_VALIDATE_EMAIL);
                $username = filter_input(INPUT_POST, 'username', FILTER_SANITIZE_STRING);
                $name = filter_input(INPUT_POST, 'name', FILTER_SANITIZE_STRING);
                // enkripsi password
                $password = password_hash($_POST["password"], PASSWORD_DEFAULT);
                $photo = filter_input(INPUT_POST, 'photo', FILTER_SANITIZE_STRING);
                $level = filter_input(INPUT_POST, 'level', FILTER_SANITIZE_STRING);

                // jalankan query
                mysqli_stmt_execute($stmt);

                // cek hasil query
                if (!$stmt) {
                  die('Query Error : '.mysqli_errno($db).' - '.mysqli_error($db));
                } else {
                  echo "Penambahan ".mysqli_stmt_affected_rows($stmt). " data berhasil<br />";
                }

                // tutup statements
                mysqli_stmt_close($stmt);

                // tutup koneksi
                mysqli_close($db);
              }
            }
            ?>

            <form enctype="multipart/form-data" action="usertambah.php" method="POST" class="form-horizontal form-label-left" novalidate>

              <p>Silahkan isi info data User
              </p>
              <span class="section"></span>

              <div class="item form-group">
                <label class="control-label col-md-3 col-sm-3 col-xs-12" for="name">Nama Lengkap<span class="required">*</span>
                </label>
                <div class="col-md-6 col-sm-6 col-xs-12">
                  <input id="name" class="form-control col-md-7 col-xs-12" data-validate-length-range="6" data-validate-words="1" name="name" placeholder="Nama Lengkap" required="required" type="text">
                </div>
              </div>
              <div class="item form-group">
                <label class="control-label col-md-3 col-sm-3 col-xs-12" for="photo">Foto<span class="required">*</span>
                </label>
                <div class="col-md-6 col-sm-6 col-xs-12">
                  <input id="photo" class="form-control col-md-7 col-xs-12" name="photo" required="required" type="file">
                </div>
              </div>
              <div class="item form-group">
                <label class="control-label col-md-3 col-sm-3 col-xs-12" for="username">Username<span class="required">*</span>
                </label>
                <div class="col-md-6 col-sm-6 col-xs-12">
                  <input id="username" class="form-control col-md-7 col-xs-12" data-validate-length-range="6" data-validate-words="1" name="username" placeholder="Username" required="required" type="text">
                </div>
              </div>
              <div class="item form-group">
                <label class="control-label col-md-3 col-sm-3 col-xs-12" for="email">Email <span class="required">*</span>
                </label>
                <div class="col-md-6 col-sm-6 col-xs-12">
                  <input type="email" id="email" name="email" required="required" class="form-control col-md-7 col-xs-12">
                </div>
              </div>
              <div class="item form-group">
                <label for="password" class="control-label col-md-3">Password</label>
                <div class="col-md-6 col-sm-6 col-xs-12">
                  <input id="password" type="password" name="password" data-validate-length="6,8" class="form-control col-md-7 col-xs-12" required="required">
                </div>
              </div>
              <div class="item form-group">
                <label for="password2" class="control-label col-md-3 col-sm-3 col-xs-12">Repeat Password</label>
                <div class="col-md-6 col-sm-6 col-xs-12">
                  <input id="password2" type="password" name="password2" data-validate-linked="password" class="form-control col-md-7 col-xs-12" required="required">
                </div>
              </div>
              <div class="item form-group">
                <label class="control-label col-md-3 col-sm-3 col-xs-12" for="level">Level Manager <span class="required">*</span></label>
                <div class="col-md-6 col-sm-6 col-xs-12">
                  <select required name="level" class="select2_single form-control">
                    <option value=""></option>
                    <option value="Super Admin">Super Admin</option>
                    <option value="Admin">Admin</option>
                    <option value="Dekan">Dekan</option>
                    <option value="Keungan">Keungan</option>
                  </select>
                </div>
              </div>
              <div class="ln_solid"></div>
              <div class="form-group">
                <div class="col-md-6 col-md-offset-3">
                  <a href="user.php" class="btn btn-primary"> Cancel</a>
                  <button id="send" type="submit" class="btn btn-success" name="savebtn">Submit</button>
                </div>
              </div>
            </form>