Part Exchange Transactions

Hi, I would like to know if there is any way to apply both a positive and negative sale in the same transaction.

For example, I am selling an item for 19.99. the customer would like to Part Exchange an item to the value of £8.00

I would like for this to be reflected on the receipt that is issued.

Is there a way to do this?

Thank You

Never mind it was straight forward really.

Just had to add text ( PX ) into the "description field" and then added a minus value ( -£3.00 )

And that's it

Also, I would like to add that I absolutely LOVE this software.