Encryption/Decryption -- Correction

Hi everyone,

In my early message I was asking some help to get me started but I was not looking for how to do the whole task... Imagine being in my position having not many programming experience for implementing different projects in the past but wanting to learn from others through guidance. Some people they just read the instruction ...and they know already what to do or where to start....but Iam not upto that level. If anyone has any idea way of improving this situation
I would take his/her advice as valuable gift.

apart from that, the encryption/ decryption program is S-P ( one permutation function and one S-boxes).

P takes 4 letter word (m1,m2,m3,m4) and returns (m1,m3,m2,m4)
and I think I can handle that without any help.

the S-box takes:
S(m1,m3) = (m1 + m3k1 (Mod 26), k2m1 + m3(Mod 26))
and same for S(m2,m4) ... k1, k2 are tha only keys they are also characters and m1...mn are the messages to be encrypted.

Thanks in advance