I guess you are done with Caesar I, aren't you?
The big problem with caesar is that it does not allow digits or other characters.
I have fixed this, and now I can use any ascii character in the plaintext.
The keyspace has increased from 26 to 128 too. \o/

Enjoy!

21 49 49 3E 20 44 49 3C 06 20 53 49 4F 20 4D 49
46 50 3F 3E 20 49 48 3F 20 47 49 4C 3F 20 3D 42
3B 46 46 3F 48 41 3F 20 43 48 20 53 49 4F 4C 20
44 49 4F 4C 48 3F 53 08 20 2E 42 43 4D 20 49 48
3F 20 51 3B 4D 20 40 3B 43 4C 46 53 20 3F 3B 4D
53 20 4E 49 20 3D 4C 3B 3D 45 08 20 31 3B 4D 48
01 4E 20 43 4E 19 20 0B 0C 12 20 45 3F 53 4D 20
43 4D 20 3B 20 4B 4F 43 4E 3F 20 4D 47 3B 46 46
20 45 3F 53 4D 4A 3B 3D 3F 06 20 4D 49 20 43 4E
20 4D 42 49 4F 46 3E 48 01 4E 20 42 3B 50 3F 20
4E 3B 45 3F 48 20 53 49 4F 20 4E 49 49 20 46 49
48 41 20 4E 49 20 3E 3F 3D 4C 53 4A 4E 20 4E 42
43 4D 20 47 3F 4D 4D 3B 41 3F 08 20 31 3F 46 46
20 3E 49 48 3F 06 20 53 49 4F 4C 20 4D 49 46 4F
4E 43 49 48 20 43 4D 20 47 47 40 3E 47 42 48 3C
3C 3F 3B 40 08