displaying a php file in an iframe using codeigniter -

good day guys, i'm trying learn codeigniter , i'm having trouble displaying php file in iframe. here's code. returns "404 page not found"

here's view:

<iframe class="tabcontent" name="myiframe" src="<?php echo site_url('pages/view_about');?     >" marginheight="8" marginwidth="8"></iframe> 

then here's controller:

  function view_about(){      $this->load->view('pages/about'); } 

here's how folders arranged

application->views->pages->about.php

application->contollers->pages.php

i add, code pasted above view located in

application->views->templates->footer.php

the iframe part of footer

php ending tag has space between

try this..

<iframe class="tabcontent" name="myiframe" src="<?php echo site_url('pages/view_about'); ?>" marginheight="8" marginwidth="8"></iframe>