How can I delete a record in a database without deleting it's related records?

I have a customer table and an order table and I want to give the user the option to delete a customer from the database without deleting that customer's orders as deleting the orders would mess up the statistics.

Each record in the order table has a field containing the customer number of the customer who made the order.

When trying to delete a customer from the customer table, I get the error "The record cannot be deleted or changed because table 'tblOrder' includes related records."

How can I delete the customer without deleting their orders?

I am using VB.NET in VS 2010

Thanks

You don't. You could add a Status value indicating that the Customer is not active but frankly I don't see the need to do anything at all.

"I don't see the need to do anything at all."
I was thinking of doing it as if a customer wanted to close their account, they would probably expect their information to be deleted.

It's not necessary though I just though it would be a nice idea, thanks for the reply.

Actually I would counsel against deleting the information in this situation even if you were still using good old paper files. Deleted records have a habit of arising to bite you in the backside a few years down the track.

Having a status that says a customer is inactive is standard in most financial packages I've worked with.

Deleting the customer row and leaving the "activity" - thus having no idea what the "name" associated with that activity would be - is really a bad idea. Very much against standard practice.