Remove 0,O,1,l from Gift Cert Generator?

Hi -

I thought I remembered a post on this a long while back but have been unable to find the answer in the forum or Wiki.  I'd like to continue using ProductCart's built-in Gift Certificate code generator but I want to prevent it from including commonly confused characters like 0,O and 1,l.   

Can anyone tell me the easiest way to modify DefaultGiftCode.asp to prevent these characters from being included in the random generator?

Thanks!

Thanks Sean.  I'm on v4.1a SP2 still and my code appears differently:

'--- Start Generating Gift Code - This is just SAMPLE CODE
                Tn1=""
                For w=1 to CodeStrLen
                    Randomize
                    myC=Fix(3*Rnd)
                    Select Case myC
                        Case 0:
                        Randomize
                        Tn1=Tn1 & Chr(Fix(26*Rnd)+65)
                        Case 1:
                        Randomize
                        Tn1=Tn1 & Cstr(Fix(10*Rnd))
                        Case 2:
                        Randomize
                        Tn1=Tn1 & Chr(Fix(26*Rnd)+97)       
                    End Select
                Next
'--- Finish Generating GiftCode   

'--- END OF GIFT CERTIFICATE CODE GERNERATOR

Thoughts?