tempdata not getting erased after given time

hi,
iam using
$this->session->set_tempdata('messege', 'hi', 5); 
in my controller to set tempdata. and i used 
<div class="card-body">
               <?php ?>
                    <span style="color: red;"><?php echo $this->session->tempdata('messege'); ?></span>   
               <?php  ?>
                                  <div class="table-responsive">


to call tempdata.But its not geting erased after 5 seconds

You mean that the displayed message is not erased after 5 seconds? That would require additional code probably javascript to accomplish. tempdata will be removed from the session user data but that has no bearing on data that is already displayed.