to update or not to update
 

I have a file with VBA that I use to generate charts and graphs - and then
save as a seperate file.
When I reopen these files, they ask if I want to update or not. I have not
noticed a difference in response regardless of how I answer the question.
What might be different if I answer one way or the other?
And if it doesn't matter, can I add some coding to tell it not to ask the
question anymore, or to have it automatically answer? What would that code
be and where would I put it?

TIA