Save Availability info in order or on invoice

[rainman2000]

Hi,

Our product availability changes automatically based on whether we have stock on hand or not. If stock is on hand then availability is "Ship same day". If no stock is on hand then availability is "Ships 7-10 business days". The problem is that the availability is not saved any when the customer places an order. So they will call and say it stated "ships same day" when they placed the order. How can we capture and save this information to the invoice or to the order?

Thanks!

Rainman