FieldView encryption challenge

[whitetiger0990]

Code:

declare function Encrypt (Msg As STRING, Pwd As STRING) As STRING
declare function Decrypt (Msg As STRING, Pwd As STRING) As STRING

function Encrypt (Msg As STRING, Pwd As STRING) As STRING
    dim pavg as integer, i as integer, i2 as integer
    for i = 1 to len(pwd)
        pavg=pavg+asc(mid$(pwd,i,1))+i
    next i
    pavg=pavg/len(pwd)
    if pavg>255 then pavg=255-pavg
    for i=1 to len(msg)
        i2=asc(mid$(msg,i,1))+pavg+i+len(pwd)
        if i2>255 then i2=255-i2
        mid$(msg,i,1)=chr$(i2)
    next i
    return msg
end function

function Decrypt (Msg As STRING, Pwd As STRING) As STRING
        dim pavg as integer, i as integer, i2 as integer
        for i = 1 to len(pwd)
                pavg=pavg+asc(mid$(pwd,i,1))+i
        next i
        pavg=pavg/len(pwd)
        if pavg>255 then pavg=255-pavg
        for i=1 to len(msg)
                i2=asc(mid$(msg,i,1))-pavg-i-len(pwd)
                if i2<0 then i2=i2+255
                mid$(msg,i,1)=chr$(i2)
        next i
        return msg
end function

Probably sucks but I'm too lazy to care =P

EDIT: *wonders why the tabs look lined up in the post but not after submitted*