View.Set ("graphics:800,600")
var c := 0
var mx, my, mb : int
for x : 0 .. 300 by 20
    for y : 0 .. 300 by 20
        drawfillbox (x, y, x + 17, y + 17, c)
        c := c + 1
    end for
end for
loop
    mousewhere (mx, my, mb)
    c := whatdotcolour (mx, my)
    locate (1, 1)
    put "Colour: ", c
    exit when mb = 1
end loop