I got this Function of the VB-World Tips section. My question is about the 'IsEven' function it seems to be calling. VB6 throws an error, sub or function not defined. Is there a reference I have to have in the project for that function? Here is the code:
Function CheckCard(CCNumber As String) As Boolean
Dim Counter As Integer, TmpInt As Integer
Dim Answer As Integer

Counter = 1
TmpInt = 0

While Counter <= Len(CCNumber)
If IsEven(Len(CCNumber)) Then
TmpInt = Val(Mid$(CCNumber, Counter, 1))
If Not IsEven(Counter) Then
TmpInt = TmpInt * 2
If TmpInt > 9 Then TmpInt = TmpInt - 9
End If
Answer = Answer + TmpInt
'Debug.Print Counter, TmpInt, Answer
Counter = Counter + 1
Else
TmpInt = Val(Mid$(CCNumber, Counter, 1))
If IsEven(Counter) Then
TmpInt = TmpInt * 2
If TmpInt > 9 Then TmpInt = TmpInt - 9
End If
Answer = Answer + TmpInt
'Debug.Print Counter, TmpInt, Answer
Counter = Counter + 1
End If
Wend

Answer = Answer Mod 10

If Answer = 0 Then CheckCard = True
End Function

Any help would be appreciated. thank you.