procedure main(av)
    &window := open("Frank Harary Normal Calculator, v2","g",
		    "image=" || (av[1] | "/home/uni1/jeffery/html/vcsc/sh2-scaled.gif"))|
	stop("this program requires sh1.gif")
    delay(1000)
    originx := 45
    originy := 20
    Fg("red")
    DrawSegment(44,19, 46, 21, 46, 19, 44, 21)

    sx1 := 294
    sy1 := 252

    sx2 := 372
    sy2 := 252

    onePixelFt := 45 / 78.0 # 45' / 78 pixels = 0.26 feet per pixel
    WAttrib("label=Scale: one pixel = " || onePixelFt || " feet")
    delay(4000)
    onePixelMt := onePixelFt / 3.281
    WAttrib("label=Scale: one pixel = " || onePixelMt || " meters")
    delay(5000)

    WAttrib("label=click any pixel for its FHN")
    while (e := Event()) ~=== "q" do {
	x := (&x - originx)
	y := (&y - originy)
	# write("FHN(",&x,",",&y,") [base ",x,",",y,"]: ", x * onePixelFt, " , ", y * onePixelFt, " in feet")
	write("FHN(",&x,",",&y,") [base ",x,",",y,"]: ",
	      x * onePixelMt, " , ", y * onePixelMt, " in FHN meters")
    }
end