Hey my dog ozzy is fifteen months and at first he started having seizures not reacting to me saying his name but then it was that he would react to his name but he has no control over his back legs. Would any body know what's wrong with him?

You should take the advice in the title of your thread.
Get him to a Vet!

No-one on here is a vet and even if they were we can't diagnose your dog over the internet.

Seizures are to be taken very seriously, they can be mild, or they can be life threatening, you need to determin the cause of them and your vet is the only one who can do that.

I second that motion. It does sound like seizures, but it could be so much more and no one would really know but a vet!
Sudden lameness can be caused by infection, allergy, it could indicate the beginning of some sort of nerve damage, it could even indicate kidney damage. Some dogs are prone to spinal problems which can cause temporary lameness. Could be virus or parasites.
So I could go on, but the point I am trying to make, is there is too many what if's...
Take him to a vet.