When an advertising contract is canceled, all unfulfilled and uninvoiced insertion orders are cancelled. An unfulfilled insertion order is one where the cancellation date is less than the Ad Date on the insertion order. If the insertion order has been invoiced, it is not canceled, even if the Ad Date on the insertion order is in the future.
To cancel the contract you are working with:
1.    From 
 the Contract Details task 
 category, click Cancel Contract.
A pop-up window displays stating, “Cancelling Contract will cause all unfulfilled 
 and uninvoiced insertion orders to be cancelled. Proceed?”
2. Click the Yes or No radio button and click OK.