Create a new channel as a copy of main.
Rename main to:
Delete main? This cannot be undone.
slider_value = function(slider, x) local s = slider if x < s.x0 then x = s.x0 end if x > s.x1 then x = s.x1 end s.x = x s.value = s.lo + (s.x-s.x0)*(s.hi-s.lo)/(s.x1-s.x0) return s.value end