Funzioni per verifica validità carte di credito

[guidoc]

Funzioni per verifica validità carte di credito

Ciao a tutti, nel norum ho trovato i seguemti scripts. qualcuno mi sa dire come applicarli?

io ho una pagina con un modulo ed ho i seguenti campi:

• Tipo carta = cctype
• Numero Carta = ccnumber
• Cod. di Controllo = cvc_code

l'ho messo on-line ma credo che non ha i controlli dovuti, ovvero non da il minimo avviso. cosa sbaglio?

<%
Function ValidCcNumber(ccnumber)
ccnumber = cleanccnum(ccnumber)
If ccnumber = "" then
validccnumber = false
Else
iseven = false
digits = ""
For i = len(ccnumber) to 1 step -1
If iseven then
digits = digits & cint(mid(ccnumber, i, 1))*2
Else
digits = digits & cint(mid(ccnumber,i,1))
End if
iseven= (not iseven)
Next
checksum = 0
For i = 1 to len(digits) Step 1
checksum = checksum + cint(mid(digits, i, 1))
Next
validccnumber = ((checksum mod 10)=0)
End if
End function
%>
<%
Function ValidCcType(ccnumber,cctype)
ValidCcType = true
If cctype = "Visa" then
If CInt(cleanccnum(Left(ccnumber,1))) <> 4 then ValidCcType = false
Elseif cctype = "MasterCard" then
If not (CInt(cleanccnum(Left(ccnumber,2))) > 50 and CInt(cleanccnum(Left(ccnumber,2))) < 56) then ValidCcType = false

Elseif cctype = "AmericanExpress" then
    If not CInt(cleanccnum(Left(ccnumber,2))) = 34 and not CInt(cleanccnum(Left(ccnumber,2))) = 37 then ValidCcType = false
Elseif cctype = "DinersClubCarteBlanche" then
    If not (CInt(cleanccnum(Left(ccnumber,3))) > 299 and CInt(cleanccnum(Left(ccnumber,3))) < 306) and not CInt(cleanccnum(Left(ccnumber,2))) = 37 and not CInt(cleanccnum(Left(ccnumber,2))) = 36 and not CInt(cleanccnum(Left(ccnumber,2))) = 38 then ValidCcType = false
Elseif cctype = "Discover" then
    If not CInt(cleanccnum(Left(ccnumber,2))) = 6011 then ValidCcType = false
End if

End function
%>
<%
Function ValidCcLength(ccnumber,cctype)
ValidCcLength = true
If cctype = "Visa" then
If Len(ccnumber) <> 16 and Len(ccnumber) <> 13 then ValidCcLength = false
Elseif cctype = "MasterCard" then
If Len(ccnumber) <> 16 then ValidCcLength = false
Elseif cctype = "AmericanExpress" then
If Len(ccnumber) <> 15 then ValidCcLength = false
Elseif cctype = "DinersClubCarteBlanche" then
If Len(ccnumber) <> 14 then ValidCcLength = false
Elseif cctype = "Discover" then
If Len(ccnumber) <> 16 then ValidCcLength = false
End if
End function
%>
<%
Function ValidCvcLength(cvc_code,cctype)
ValidCvcLength = true
If cctype = "Visa" then
If Len(cvc_code) <> 3 then ValidCvcLength = false
Elseif cctype = "MasterCard" then
If Len(cvc_code) <> 3 then ValidCvcLength = false
Elseif cctype = "AmericanExpress" then
If Len(cvc_code) <> 4 then ValidCvcLength = false
Elseif cctype = "DinersClubCarteBlanche" then
If Len(cvc_code) <> 3 then ValidCvcLength = false
Elseif cctype = "Discover" then
If Len(cvc_code) <> 3 then ValidCvcLength = false
End if
End function
%>
<%
Function cleanccnum(ccnumber)
For i = 1 to len(ccnumber)
If isnumeric (mid(ccnumber, i, 1)) then
cleanccnum = cleanccnum & mid(ccnumber, i,1)
End if
Next
End function
%>

Grazie