Fixed X position but freely moving Y positon?

[Scripter]

I have no idea how to make the X value fixed.

I'm guessing you are using FixedVelocity, and have a FixedRotation in the brick.

[lua]
box1.FixedVelocity.Velocity = Vec2D(0, 5)
[/lua]

Otherwise, if all you want to do is move a Fixed brick up, you would want...

[lua]
while true do
sleep(0.1)
box1.Position = box1.Position + Vec2D(0,1)
end
[/lua]