How to make a button that moves down when the player walks over it?

[Grigri]

Hey, so i am currently developing a map pack (atleast i am trying to) and i would like to add buttons, but it wouldnt look to well if the player walks over it and it doesnt move, how do you make it move down? im pretty new to zone builder so any nod into the right direction is appreaciated (for example take the button from techno hill zone act 2 that you need to press to make the purple goo rise upwards)