Registration of software code

On Tue, 23 Sep 2003 09:13:28 +1000, "dixie" <di****@dogmail.com>
wrote:

Here is one option:
Turn the string into a number (e.g. by stripping all non-numerics).
Call this number A. Then calculate the difference between that number
and the number 123456789 (or any other "magic number") called number
B. The user would have to enter the resulting number C (=A-B) in order
to enable the software.
Variants:
* A is created not just by stripping the non-numerics, but these
non-numerics actually modify the numerics. E.g. A adds 1, B adds 2,
etc.
* B is modified by the non-numerics in a similar way.
* C is modified by the current date (e.g. subtract the number of days
in the current year) so the code can be used only once.

The sky is the limit in how complicated you can make these algorithms.

Happy programming.

-Tom.

Is there some relatively simple way that I could create some sort of number
from a series of letters and numbers in a field on a form and then when a
person purchases the software, supply a matching number to their unique
number that could be put into a field in a table that would then enable the
software.

I think the idea would probably work, but how do I generate the number. The
number would come from something like A03078989-BT39 which is a unique
serial number for one copy of the software. Just using this number would be
easily guessed. How do I process the serial number to produce a unique
number?

Any ideas.

dixie

Tom, could you give me an example of using VBA code for stripping non
numerics out of something like A1233WB25?

dixie

"Tom van Stiphout" <to*****@no.spam.cox.net> wrote in message
news:8c********************************@4ax.com...

On Tue, 23 Sep 2003 09:13:28 +1000, "dixie" <di****@dogmail.com>
wrote:

Here is one option:
Turn the string into a number (e.g. by stripping all non-numerics).
Call this number A. Then calculate the difference between that number
and the number 123456789 (or any other "magic number") called number
B. The user would have to enter the resulting number C (=A-B) in order
to enable the software.
Variants:
* A is created not just by stripping the non-numerics, but these
non-numerics actually modify the numerics. E.g. A adds 1, B adds 2,
etc.
* B is modified by the non-numerics in a similar way.
* C is modified by the current date (e.g. subtract the number of days
in the current year) so the code can be used only once.

The sky is the limit in how complicated you can make these algorithms.

Happy programming.

-Tom.

Is there some relatively simple way that I could create some sort of numberfrom a series of letters and numbers in a field on a form and then when a
person purchases the software, supply a matching number to their unique
number that could be put into a field in a table that would then enable thesoftware.

I think the idea would probably work, but how do I generate the number. Thenumber would come from something like A03078989-BT39 which is a unique
serial number for one copy of the software. Just using this number would beeasily guessed. How do I process the serial number to produce a unique
number?

Any ideas.

dixie

cinch...

Option Compare Database
Option Explicit

Public Function JustAlpha(strAlphaNum As String) As String
Dim strTemp As String
Dim intCounter As Integer
Dim strChar As String

For intCounter = 1 To Len(strAlphaNum)
strChar = Mid$(strAlphaNum, intCounter, 1)
If Not IsNumeric(strChar) Then
strTemp = strTemp & strChar
End If
Next intCounter
JustAlpha = strTemp
End Function

Umm... whaddaya return if it's a string of just numbers?

On 24 Sep 2003 19:46:11 -0700, pi********@hotmail.com (Pieter Linden)
wrote:

Nice function - I would call it JustNumeric.
At the bottom of the function I might write:
if Len(strTemp)=0 then strTemp="0"

-Tom.

cinch...

Option Compare Database
Option Explicit

Public Function JustAlpha(strAlphaNum As String) As String
Dim strTemp As String
Dim intCounter As Integer
Dim strChar As String

For intCounter = 1 To Len(strAlphaNum)
strChar = Mid$(strAlphaNum, intCounter, 1)
If Not IsNumeric(strChar) Then
strTemp = strTemp & strChar
End If
Next intCounter
JustAlpha = strTemp
End Function

Umm... whaddaya return if it's a string of just numbers?