Here is the horizontal version of the scalar-slider

scalar-hslider is a graphic slider overlaying an [Hslider], and using the same process as the scalar-knob and scalar-slider.
In the help file I had put a wireless way to access the underlying vslider/hslider, I now realise this will prevent any scaling to the underling slider and cause it to fail. In the scalar-hslider help file there is an alternative hard wired version that should still allow later sizing.