input Validation

[injanib]

I have an unbound field that is used to enter for a new password.

On the event, before the input is encrypted and written into the table, I would like to check for the string to make sure it contains at least one upper case, one lower case and one number.

How can I go about doing this?

Thanks in advance.

[June7]

Don't think will be easy because VBA and Access are not case sensitive - "jrh" Like "*[A-Z]*" will return True

You need to test the entry against 3 criteria. The number part is easy enough
If Not stringIn Like "*[0-9]*" Then
MsgBox "Not a valid password. Try again."
End If

Here is possible way to check for letter case. Write a custom function that can be called in the above If Then. The function would take the user entry as input argument, convert each character to ASCII equivalent and test if the value falls within the ASCII range for Upper or Lower Case or a Number.

Number: ASC(strChar) >= 48 And ASC(strChar) <= 57
Lower Case: ASC(strChar) >= 65 And ASC(strChar) <= 90
Upper Case: ASC(strChar) >= 97 And ASC(strChar) <= 122

Have 3 boolean variables in the code that would be set to True if related condition met. If all 3 True then the function returns True (valid password) otherwise False (invalid password).

[injanib]

thanks, but doesn't the Asc function return the ASCii equivalent of the first character in a string. I tried this, but the function returns falls no matter what, and I think it is because each case looks for the related condition in the first character of the string.

Any other suggestions?

[orange]

June gave you great advice.
Here's some sample code to show how it works. You'll have to change it to make it a function. Sometimes passwords must be a minimum length as well.

Sub checkAlphaNumberAndLower()
'Number: ASC(strChar) >= 48 And ASC(strChar) <= 57
'Lower Case: ASC(strChar) >= 65 And ASC(strChar) <= 90
'Upper Case: ASC(strChar) >= 97 And ASC(strChar) <= 122
Dim str As String
Dim strChar As String
Dim i As Integer
Dim LowerFound As Boolean
Dim UpperFound As Boolean
Dim NumericFound As Boolean
On Error GoTo checkAlphaNumberAndLower_Error

LowerFound = False
UpperFound = False
NumericFound = False

str = "BAD" '"Go0d"
'UpperCheck
For i = 1 To Len(str)
strChar = Mid(str, i, 1)
If Asc(strChar) >= 97 And Asc(strChar) <= 122 Then
UpperFound = True
Exit For
Else
End If
Next

'LowerCheck
For i = 1 To Len(str)
strChar = Mid(str, i, 1)
If Asc(strChar) >= 65 And Asc(strChar) <= 90 Then
LowerFound = True
Exit For
Else
End If
Next

'NumericCheck
For i = 1 To Len(str)
strChar = Mid(str, i, 1)
If Asc(strChar) >= 48 And Asc(strChar) <= 57 Then
NumericFound = True
Exit For
Else
End If
Next

'Check Results
If UpperFound = True And _
LowerFound = True And _
NumericFound = True Then
MsgBox str & " is a valid password "
Else
MsgBox str & " is NOT A VALID PASSWORD !!"
End If

On Error GoTo 0
Exit Sub

checkAlphaNumberAndLower_Error:

MsgBox "Error " & Err.number & " (" & Err.Description & ") in procedure checkAlphaNumberAndLower of Module AWF_Related"
End Sub

[injanib]

Ahh! so that was the trick to make it search the entire length of the string. Sorry I wasn't smart enough to implement June7's suggestion the right way. But this works great, and I also included the validation rule for the length of the password and also the presence of special character in it in the function. It works like magic. Thanks June7 and Orange.