Decode or encode .txt messages based on character mapping
located in a .csv file. Currently can only encode or decode
English letter characters and not other symbols such as .,
!, etc. It will also keep capital lettering the same as the
original message.
a,z
b,a
c,b
d,c
e,d
f,e
g,f
h,g
i,h
j,i
k,j
l,k
m,l
n,m
o,n
p,o
q,p
r,q
s,r
t,s
u,t
v,u
w,v
x,w
y,x
z,y