VB6 Function for AlphaNumeric Checking

The following are some useful VB6 validation checking functions.

Public Function IsAlphaBetical(TestString As String) As Boolean

Dim sTemp As String
Dim iLen As Integer
Dim iCtr As Integer
Dim sChar As String

'returns true if all characters in a string are alphabetical
'returns false otherwise or for empty string

sTemp = TestString
iLen = Len(sTemp)
If iLen > 0 Then
For iCtr = 1 To iLen
sChar = Mid(sTemp, iCtr, 1)
If Not sChar Like "[A-Za-z]" Then Exit Function
Next

IsAlphaBetical = True
End If

End Function

Public Function IsAlphaNumeric(TestString As String) As Boolean

Dim sTemp As String
Dim iLen As Integer
Dim iCtr As Integer
Dim sChar As String

'returns true if all characters in a string are alphabetical
' or numeric
'returns false otherwise or for empty string

sTemp = TestString
iLen = Len(sTemp)
If iLen > 0 Then
For iCtr = 1 To iLen
sChar = Mid(sTemp, iCtr, 1)
If Not sChar Like "[0-9A-Za-z]" Then Exit Function
Next

IsAlphaNumeric = True
End If

End Function

Public Function IsNumericOnly(TestString As String) As Boolean

Dim sTemp As String
Dim iLen As Integer
Dim iCtr As Integer
Dim sChar As String

'returns true if all characters in string are numeric
'returns false otherwise or for empty string

'this is different than VB's isNumeric
'isNumeric returns true for something like 90.09
'This function will return false

sTemp = TestString
iLen = Len(sTemp)
If iLen > 0 Then
For iCtr = 1 To iLen
sChar = Mid(sTemp, iCtr, 1)
If Not sChar Like "[0-9]" Then Exit Function
Next

IsNumericOnly = True
End If

End Function