Long story short I am trying to set up a wheel of fortune installation for a music museum, all pro-bono as it were, it's all run on a voluntary basis...

the installation is very basic in principle click the button and spin the wheel and depending on where it stops - the user gets given a lyric... there are only a set amount of lyrics / lines - roughly 19/20...

ideally what the museum would like to do is to randomly award a prize - but I am at a loss of how to do this - I have attached the docs to view... it is set up to work in a standalone environment (no internet connection etc...) 

As said, I really at a loss as to how I can do this - the wheel itself is working just fine and doing exactly what it should do... but is there a simple snippet that I can add to randomly swap on of the lyrics with the line "you've won a...." based on a list of prizes?

Really hope someone has time, knowledge and inclination to put me right on this 

Here's hoping 
***crosses fingers***