Invalid Username and Password in Codeignter

Step 1 :- $this->session->set_flashdata(‘login_failed’,’Invalid Username/password’);

step 2 :- <?php if($error=$this->session->flashdata(‘login_failed’)):?>
<div class=”row”>
<div class=”col-lg-6″>
<div class=”alert alert-dismissible alert-primary”>
<button type=”button” class=”close” data-dismiss=”alert”>&times;</button>
<?= $error;?>
</div>
</div>
</div>
<?php endif;?>