1 2 3 4 5 6 7 8 9 10 | SCREEN 12clr1 = 6clr2 = 7FOR y = 20 TO 370 STEP 50 FOR x = 20 TO 370 STEP 50 LINE (x, y)-(x + 50, y + 50), clr1, BF SWAP clr1, clr2 NEXT x SWAP clr1, clr2NEXT y |