Cannot display popup when button is clicked

I am developing a website in php using codeigniter. I need to add a pop window when I click the "Book Now" button in my view (profile.php), the following code works fine on the HTML page without any problems, but when I mix php, the popup window comes up and the disperser is fast. This is the code I'm using. I can’t find the problem and heed the quick help. Can someone explain the error here?

this is code that uses

<button class="btn btn-danger" id="buy-btn">BOOK NOW</button>
        <!-- Modal -->
         <div class="modal fade" id="moreInfo" tabindex="-1" role="dialog" aria-labelledby="moreInfoLabel" aria-hidden="true">
       <div class="modal-dialog">
        <div class="modal-content">
            <div class="modal-header">
            <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
            <h4 class="modal-title" id="moreInfoLabel"><?php echo $package_data['PackageTitle']; ?></h4>
           </div>
          <div class="modal-body">
        <p>Number of Peaple :<?php echo $tour_data['Visitors']?></p>
        <p>Itenaries : Elephant Blues, Gallface, Brown Circus, Nelum Tower</p>
        <p>Method of Travel : Taxi Service</p>
        <p>Total Time Estimated : 6 Hours</p>
        <hr>
        <h4>Terms and Conditions</h4>
            <p><?php echo $tour_data['TermsAndConditions']; ?></p>
        </div>
        <div class="modal-footer">
        <button type="button" class="btn btn-primary center-block">Book Now</button>
        </div>
        </div><!-- /.modal-content -->
    </div><!-- /.modal-dialog -->
   </div><!-- /.modal -->