loop
drawfillbox (321, 185, 392, 204, brown)
drawfillbox (390, 192, 398, 200, brown)
drawfilloval (329, 196, 7, 7, red)
drawfilloval (352, 197, 7, 7, 68)
drawfilloval (375, 197, 7, 7, green)
drawfilloval (375, 197, 7, 7, brightgreen)
delay (1000)
drawfilloval (375, 197, 7, 7, green)
drawfilloval (352, 197, 7, 7, yellow)
delay (1000)
drawfilloval (352, 197, 7, 7, 68)
drawfilloval (375, 197, 7, 7, green)
drawfilloval (329, 196, 7, 7, brightred)
delay (1000)
end loop
It's terrible code but I'm studying for physics (even though I'm on compsci... :S) and I don't feel like thinking too hard
You need to simply use delays for such a simple idea like this and a loop if you want to constantly run through the lights.