Urgent Ryanair Baggage Help!

Ryan Air Bags

My daughter is travelling tomorrow, I am trying to add a bag to her booking. When I go into the section Manage my Booking etc. and the section add bag etc I select to add the bag the price of 20 euro comes up and I press continue then a little box comes up and says "cabin bag - select option" I do not seem to be able to add my bag - when I press continue this little box comes up and I do not know what I am doing wrong. Could someone please throw some light on this for me! ASAP

I have finally managed to add the bag!! It suddenly struck me that I had to click "NO" in the section where they have their new cases advertised for sale at the to of the page. It is so obvious now, I feel a right fool now as I have spent the past half hour trying to add the bag.