What 2731yugeip said is partially correct, you do need to use the layer 2 rise up command to make scrolling going down, and the layer 2 falls command to make scrolling go up (as strange as it is, that's the truth there). Both require the vertical layer 1 scroling to be set to "No Vertical or Horizontal Scroll" to work right.
To make the screen scroll down, first set the amount of screens to just one (only way this works), then you need to set the starting position on the top screen (I used E for the X coordinate, and 9 for the Y coordinate in one of the rooms in a level of mine). From here, build the floor on layer 1 (if you want to make things a little tougher, you can put in a spiked ceiling), then put everything else on layer 2, such as floor spikes, if you want to make it hard enough. You also have to put a layer 2 floor directly underneath the startkng position in order for this to work. Lastly, put the FG and BG settings (under the Main Entrance menu) to 00 and 60 respectively.
To make the screen scroll up, make the starting position on the screen second from the bottom (it should be C), this time, you need to put the level itself on layer 2. If you want to make the area more of a chase, you can put something hazardous on layer 1 that follows you, such as a bed of spikes or lava. Note, that when using this properly, the screen shakes a bit before it starts to scroll up, but that's okay.
Oh, a couple more things, one, if you plan to use enemies with either kind of scrolling, it's best to use a generator (I made a generator for Eeries in wave motion for one area, and I used the appearing/disappearing Boo Buddies in another), as sprites won't work too well with the layer 2 areas in either, two, for the exit, you need to place it on the same screen you start on, in both cases.
If you need more help with either, I'll be here.
