How to? Slider Effect

Hey everyone! I have a layout with 20 levels to select from. I want to add a Left and Right arrow so that a player can view the next 20 levels. I don't want to change the Layout though. Is there a way I can have 20 sprites slide in at once? Hope I explained myself clearly.

Here's a photo of what I mean.

<img src="http://img404.imageshack.us/img404/6540/support003.png" border="0" />

not sure my solution is the best, but:

You set your Background layer parallax to (0, 0)

You createanother layer for your button's levels, with a parallax of (100, 0), to make this layer scroll on the X axis

and You use the scrolling to make it scroll (a ScrollTo behaviour on a sprite maybe, and you move the sprite when necessary)

Theres the easy tween behaviour, or you could lerp it.

put sprites into a family.

if left arrow pressed and variable = stop, set family variable "target_pos" to self.x - what ever, set variable to left.

if variable = left,

sub event

distance to "target_pos" > 1, set family.sprites x pos to lerp(self.x, "target_pos", dt*speed)

distance to "target_pos" <= to 1 set variable to stop.