<%declaration section
var startpointx, startpointy : int := 0
var endpointx, endpointy : int := 50
var key : string (1)

%set screen mode and size
setscreen ("graphics:400;400")
setscreen ("noecho")
setscreen ("nocursor")
setscreen ("offscreenonly")

procedure display
    drawfillbox (startpointx, startpointy, endpointx, endpointy, white)
    drawfillbox (startpointx + 1, startpointy + 1, endpointx - 1, endpointy - 1, blue)
    getch (key)
    if key = chr (200) then
        startpointy := startpointy + 1
        endpointy := endpointy + 1
    elsif key = chr (208) then
        startpointy := startpointy - 1
        endpointy := endpointy - 1
    elsif key = chr (205) then
        startpointx := startpointx + 1
        endpointx := endpointx + 1
    else
        if key = chr (203) then
            startpointx := startpointx - 1
            endpointx := endpointx - 1
        else
            if (startpointx = 0 or startpointx = 350) and (startpointy = 0 or startpointy = 350) and (endpointx = 399 or endpointy = 0) and (endpointy = 399 or endpointy = 0) then
                startpointx := startpointx-1
                startpointy := startpointy-1
                endpointy := endpointy-1
                endpointx := endpointx-1
            end if
        end if
    end if
    View.Update
end display
%main program
loop
    display
    exit when key = chr (27)
end loop
>

if x >= maxx then
     x = maxx
elsif x <= 0 then
     x = 0
end if
if y >= maxy then
     y = maxy
elsif y <= 0 then
     y = 0
end if

if key = chr (200) and endpointY < maxy then
    %insert movement here
end if