What is the best thing to do if your child is having a seizure?

Protect. Make sure child on his side, no hard object to cause trauma, breathing is good, call for help, see what is the medicines available.
First aide. Place the child on the floor, away from furniture with sharp angles. On the floor so if you have to go to the phone to call 911, there will be no danger of falling. Turn on the side. If the mouth is open, put something soft between the teeth and sweep the mouth to clear foreign objects. If the mouth is closed, do not pry open. If seizure lasts more than 2-3 minutes call 911.