Session or Request.Form for accessing Sensitive data

[Microsoft]

Is getting sensitive information (ie Credit Card info) from either:
- Session("CreditCardNo")
- Or
- Request.Form(tbCreditCardNo) - From where the card was entered in.

What is the most secure method?

I have one form that collects billind data, then I send the user to another
page where the order is processed. I am needing to know where to store the
variable (credit card no) when changing pages?

TIA,

Steve Wofford