need help with the chrW function and handling invalid inputs

[Apocmonk]

At the moment im working on an encryption program, just to prove something to myself. At the moment I have a problem, when I run the program it will drop a few characters and return wrong characters, here is the encrypter code.

[code=vbnet]
Dim x As Int64
Dim y As Int64
Dim z As Int64
Dim chrpos As Int64
Dim chrcode As Int64
Dim str As String
Dim Buffstr As String
Buffstr = ""
str = TBX1.Text
For z = 0 To 10
Buffstr = ""
For x = 0 To str.Length - 1
For y = -32768 To 65535
If str.Chars(x) = ChrW(y) Then
chrcode = y
chrpos = x
End If
Next
chrcode = chrcode + ((chrpos * chrpos))
While chrcode > 65535
chrcode -= 65535
End While
While chrcode <= -32768
chrcode += 32768
End While
Buffstr = Buffstr & ChrW(chrcode)
Next
str = Buffstr
Next
tbx2.Text = str
[/code]
notes:
> tbx1 and 2 are textboxes for input/output

> the difference between the encryption and decryption code is that the decryption is the addition the square of the position of the characters and the encryption is the subraction of the sqaure of the position of the characters

>when I run the code above and encrypt 195 1's then decrypt the output it rerurns

111111111111111 111111111111111 111111111111111 111111111111111 111111111111111 111222222222222 222222222222222 222223333333333 333333333333334 444444444444444 444445555555555 555555556666666 66666666667耷77耷

the output should be 195 1's but it is as above

in advance thank you for the help

[tlhintoq]

Original Poster: I have xxx, then do yyy then zzz happens. Here's my code ...

Ok. You know what you have.
What you don't have is a question. Nobody here knows why you posted this since you haven't asked anything, or exception or description of any error messages you are getting. You haven't described anything that is broken, or any 'expected' results versus 'actual' results.
I recommend you read the FAQ about How to ask a good question so the volunteers will be able to help

[Apocmonk]

Ok. You know what you have.
What you don't have is a question. Nobody here knows why you posted this since you haven't asked anything, or exception or description of any error messages you are getting. You haven't described anything that is broken, or any 'expected' results versus 'actual' results.
I recommend you read the FAQ about How to ask a good question so the volunteers will be able to help

I have ammended my question and added the actual and expected results. Tahnkyou for thhe pointers