Michael, Thanks for your response. Please forgive my ignorance if this is obvious. I am used to working with just VB.net and ASP.net so I am not that familiar with html controls and javascript but what do you do with your fingerprint after you generate it. Don't you have to set the value of the hidden input control to the fingerprint? I'm not sure how to go about this. Also, you have _UTC but it is never used anywhere. Did you mean for it to be used in _FPString instead of UTCDate? Thanks for any help you can give. I have gotten zero response from authorize.net. -Jennifer *** Sent via Developersdex http://www.developersdex.com ***