Add back buttons on NextGEN Gallery Version 2.0.21

I am using NextGEN Gallery Version 2.0.21 and I would like to add a back button on all the galleries. On the older versions of NextGEN Gallery I would use this code on view/gallery.php and on view/album-compact.php

</div>
<FORM><INPUT Type=”button” VALUE=”<<< Go Back” onClick=”history.go(-1);return true;”></FORM>
<?php endif; ?>

With this new version, I don’t know where to find view/gallery.php and on view/album-compact.php though.

Please advice.

http://wordpress.org/plugins/nextgen-gallery/