28. FrozenAccount [ A ] = True
FrozenAccount [ B ] = False
FrozenAccount [ C ] = False
Freeze!
C
A B
29. FrozenAccount [ A ] = True
FrozenAccount [ B ] = False
FrozenAccount [ C ] = False
A
C
B
transfer( B, 100)
msg.sender = A
30. FrozenAccount [ A ] = True
FrozenAccount [ B ] = False
FrozenAccount [ C ] = False
A
C
B
approve( C, 100)
transferFrom( A, B,100)
;;;
msg.sender = C