Pronto M51 was plugged in and was turned on to use. The chair never moved and their were sparks from the joystick. Now the chair will not work. What can i do to fix this problem?

Power chairs are not designed to operate while they are plugged into the charger, as it will drag the charger around or you may run over the cord, therefore most power chairs have an inhibit feature that prevents the power chair from moving while it is connected to the charger.
If you saw sparks from the joystick, something has shorted out the controller; moisture or condensation may have gotten into the controller or there may have been a manufacturing defect.
I do not think there is anything you can do at this point except to contact the manufacturer or the place where you purchased the power chair to arrange a service call and replacement of the joystick/controller. If your insurance bought the power chair for you they may cover the repair if it is not covered by the warranty.
Good luck!