Wiremod question

Well im making a flyable, drivable fort, and im pretty new at wirmeod. I have two buttons to increase and decrease altitude. i link all the hoverballs to one of my buttons so it can go up, but since you can only use zvelocity on one button, i cant do anything with the other button to go down, and when i do, i cant go up anymore. is there some way i can use two zvelocities for one pair of hoverballs?

Use a adv pod controller and put it to a seat and use a arithmatic chip set on A and B and put the zvelocity to the chip and once you do all the hoverballs A is up and B is down
Wire the chip to the adv pod
I.E. A=Up=Space B=Down=Alt

Rewrite that in english please.

[editline]01:27PM[/editline]

Spawn 2 buttons. Both using the settings: Onvalue: 1, Offvalue: 0, Toggle: not checked.
Go to Gate - Arithmetic, spawn a Subtract gate.
Wire “A” of the subtract gate to one of the buttons, and “B” of the subtract gate to the other button.
Wire “ZVelocity” of all hoverballs to the subtract gate.

Edit: This is pretty much what the above person was getting at, except I couldn’t understand his english.