Thanks for the comments guys
The game was designed to be turn based, and you can switch between active tanks on your team using the ctrl key.
Also, the turret is controlled independantly from the tank chassis by using the z & x keys.
There is some other stuff, but that's all included in the readme file.
Anyway, thanks for your input, I might get back to this project after I have a working version of "DropShip" - my latest effort.
There is nothing in life which can't be improved with either Monkeys, Ninjas or Pirates. Or Sheep.