Any suggestions will be helpful...

I have been asked to redesign a web site. The site accesses a database on an AS 400. I know nothing about an AS 400. I do know SQL (Oracle, MS SQL, My SQL, etc). What is the first step I need to take to determine if I am capable of dealing with this situation. I do not want to get in over my head and upset the customer. I have been honest that I am not familial with that system but I would take a look at it to see If I would be able to work through it. With no experience with the AS 400 would I have any problem just "winging it"?

hmm... i don't know nothing about it too... what did Google say about it??