an example can be found on AMOSPro_Examples:Examples/H-3/Help_33.AMOS
Draws a horizontal slider bar on the screen. With a little work, it's possible to animate this to generate attractive scroll bars for your program.
Hslider tx,ty To bx,by,total,pos,size
total sets the number of units the bar is divided into.
pos specifies the postion of the slider box relative to the start of
the bar, in the units your entered in total.
size fixes the size of the slider box.