How I disconnect the button next page in the opening to a page and the asset after some time?

If you mean "disable" Next button, then you can use NAVIGATION action attached to any suitable object event, or place actionbox with this action on the timeline.
Some navigation tricks are also discussed <a href="http://courselab.com/db/cle/B3EB288E7704EC10C3257308002B6A78/main_id/DEB1AE8A7B1B3576C3256FCF0055974C/extended/1/forum.html">in this topic</a>.