Infinite Menu - slight problem....Can't figure it out

[prestigeinteractive]

Hello there,

I am trying to make an infinite menu that slide up and down the screen. I have followed the tutorial on this site, but modified the code to produce an up and down movement of the buttons. However, they don't form the continuous look of the samples on the site. It tends to reset itself each time it goes beyond the parameters set. I can't quite figure out the parameters to make it work properly.

Here is the code i placed on the movie. I've tinkered with the numbers, so they may be nowhere near what they should be.

onClipEvent (load)
{
ycenter=120;
speed=1/10;
}
onClipEvent (enterFrame)
{
var distance=_root._ymouse-ycenter;
_y+=(distance*speed);
if (_y > 0) _y=-240;
if (_y < -240) _y=0;
}

I would greatly appreciate anyone's help on this. I've attached the file in case you want to take a look at it.

Thanks for your time.

Greg White