Movement with Acceleration [renamed]

Heyo!

Ok, i have this kinda difficult question (i think it is…) :

Let’s say i have a button, and a movie, when i click on the button, i want the movie to move to another position with an accelerating effect ! How would i achieve this?

For the putton i have this code:

on (release){
instanceNameOfMovie._y = a value;
}

How can i modify it so that it will move to that value smoothly? i mean with an accelerating effect