Thanks guy's.
Finally got all 3 player special abilities coded.
This last one is a simple bubble swap, mainly because it's the most common power up and so can't be too powerful.
Anyway it turned out a bit more work then i thought, mainly because i had to work out what bubble types were not left on the board or currently next to be fired.
After a few false starts i just dumped everything into a function.
Also added a slight effect to the hazard.
Latest version here. https://dl.dropboxusercontent.com/u/159885981/pb13/index.html