SCREEN 9 '640 x 350
      '15 - wight, 7 - light, 8 - gray, & 0 - black
PAINT (1, 1), 7
X1 = 10
Y1 = 10
X2 = 30
Y2 = 30
DO
GOSUB PUSHED
FOR A = 1 TO 3000: NEXT A
GOSUB UNPUSHED
FOR A = 1 TO 3000: NEXT A
LOOP UNTIL INKEY$ = "q"
END



UNPUSHED:
LINE (X1, Y1)-(X1, Y2 - 1), 15
LINE (X1, Y1)-(X2 - 1, Y1), 15
LINE (X2 - 1, Y1 + 1)-(X2 - 1, Y2 - 1), 8
LINE (X2 - 1, Y2 - 1)-(X1 + 1, Y2 - 1), 8
LINE (X1, Y2)-(X2, Y2), 0
LINE (X2, Y2)-(X2, Y1), 0
LINE (X1 + 1, Y1 + 1)-(X2 - 2, Y2 - 2), 7, BF
RETURN




PUSHED:
LINE (X1, Y1)-(X1, Y2), 0
LINE (X1, Y1)-(X2, Y1), 0
LINE (X1 + 1, Y1 + 1)-(X1 + 1, Y2 - 1), 8
LINE (X1 + 1, Y1 + 1)-(X2 - 1, Y1 + 1), 8
LINE (X1 + 1, Y2)-(X2, Y2), 15
LINE (X2, Y2)-(X2, Y1 + 1), 15
LINE (X1 + 2, Y1 + 2)-(X2 - 1, Y2 - 1), 7, BF
RETURN