Take away the ability to easily DELETE an invoice

As a brand new user, I inadvertently 'deleted' my very first invoice (#001) having spent several hours working on it! I am not sure HOW I did it. After speaking to your help team I think I may have hit cancel. Can I suggest that cancel is perhaps changed to DELETE with the opportunity to hover your mouse over this option with a note that comes up saying you are about to DELETE your invoice. The whole premise behind this type of accounting software is to create a sequentail record of invoices and to simply delete one without any warning is frustrating. So frustrating that I am considering cancelling this book and starting again so that I can regain invoice #001!