unable to open modal pop up window

i want to open modal window using php codeigniter. but the error occured.

Code:

<td>

<button class="btn btn-warning" onclick="edit_book(<?php echo $book['appno'];?>)"><i class="glyphicon glyphicon-pencil"></i></button> </td>

Uncaught ReferenceError: app005 is not defined

   at HTMLButtonElement.onclick (v_dashboard:190