Encryption Function

Function Encrypt(text As String, pw As String, type_of As Boolean) As String
'Declaring variables
Dim x As Integer
Dim i As Integer
Dim a As Integer
Dim text_chr As String
Dim text_asc As Integer
Dim pw_chr As String
Dim pw_asc As Integer
Dim fin As String
Dim fin_chr As String
Dim fin_asc As Integer

'if type_of = true then Encrypt
'if type_of = False then Decrypt
Call percent(Picture1, 0) 'clear percent
'making sure there is text to encrypt and a password
'to go with it
If Len(text$) = 0 Then Exit Function
If Len(pw$) = 0 Then Exit Function

x% = 1
'the X variable is the loop that goes through the password
'characters individually through the encrpytion processes
'X = 1 to set the loop at the first character
For i% = 1 To Len(text$) 'start of encrpyt loop
    'taking out characters from text to encrypt
    'the single character
    text_chr$ = Mid(text$, i, 1)
    'changing the character to its ASCII value to
    'easily change the character for encrypting
    text_asc% = Asc(text_chr$)
    'doing the same process with the password
    'using the X variable
    pw_chr$ = Mid(pw$, x, 1)
    pw_asc% = Asc(pw_chr$)
    'adding up variable to continue loop through different
    'characters within the password
    x% = x% + 1
    If x% > Len(pw$) Then x% = 1 'restarting password loop
    'Case to check if the user is Encrypting or Decrypting the text
    Select Case type_of
    Case True: 'Encrypting
        'adding the characters of both string and password
        fin_asc% = text_asc% + pw_asc%
        'making sure the final_asc will equal a valid ASCII character
        If fin_asc% > 255 Then
            'Character was an invalid character so we modify it
            'to equal a valid character
            a% = fin_asc% - 255
            fin_chr$ = Chr$(a%)
        Else
            'character was valid;D
            fin_chr$ = Chr$(fin_asc%)
        End If
    Case False: 'Decrypting
        'here we subtract the characters...does the opposite of
        'what encrypting does to put it back in its
        'original state, which is why it's called Decrypting
        fin_asc% = text_asc% - pw_asc% 'subtracting character values
        If fin_asc% < 1 Then   'checking for invalid character
            'invalid character..fixing problem =)
            a% = fin_asc% + 255
            fin_chr$ = Chr$(a%)
        Else
            'it was all good.
            fin_chr$ = Chr$(fin_asc%)
        End If
    End Select 'End of case
    'adding the final encrypted character to a string
    'to be later shown in its final state at the end
    fin$ = fin$ & fin_chr$
    'thought i'd be mr. fancy pants by adding a little
    'percentage bar =)
    Call percent(Picture1, CInt((i / Len(text) * 100)))
Next 'continuing loop =)
'finalizing function to equal the final encrypted string
Encrypt$ = fin$
DoEvents
Call percent(Picture1, 0)
End Function