Public Function CreditCardType(ByVal CardNo As String) As String

'*CARD TYPES            *PREFIX           *WIDTH
'American Express       34, 37            15
'Diners Club            300 to 305, 36    14
'Carte Blanche          38                14
'Discover               6011              16
'EnRoute                2014, 2149        15
'JCB                    3                 16
'JCB                    2131, 1800        15
'Master Card            51 to 55          16
'Visa                   4                 13, 16
    
'Just in case nothing is found
CreditCardType = "Unknown"

'Remove all spaces and dashes from the passed string
CardNo = Replace(Replace(CardNo, " ", ""), "-", "")

'Check that the minimum length of the string isn't less
'than fourteen characters and -is- numeric
If Len(CardNo) < 14 Or Not IsNumeric(CardNo) Then Exit Function

'Check the first two digits first
Select Case CInt(Left(CardNo, 2))
   Case 34, 37
      CreditCardType = "American Express"
   Case 36
      CreditCardType = "Diners Club"
   Case 38
      CreditCardType = "Carte Blanche"
   Case 51 To 55
      CreditCardType = "Master Card"
   Case Else

      'None of the above - so check the
	  'first four digits collectively
      Select Case CInt(Left(CardNo, 4))
	  
         Case 2014, 2149
            CreditCardType = "EnRoute"
         Case 2131, 1800
            CreditCardType = "JCB"
         Case 6011
            CreditCardType = "Discover"
         Case Else

            'None of the above - so check the
            'first three digits collectively
            Select Case CInt(Left(CardNo, 3))
               Case 300 To 305
                  CreditCardType = "American Diners Club"
               Case Else
         
               'None of the above -
               'so simply check the first digit
               Select Case CInt(Left(CardNo, 1))
                  Case 3
                     CreditCardType = "JCB"
                  Case 4
                    CreditCardType = "Visa"
               End Select

            End Select
			
      End Select
	  
End Select

End Function

Private Sub Form_Load()

   ' Put here the credit card number you want to check




    MsgBox CreditCardType("5454 1234 4321 1234")
End Sub