Has your dog been having accidents a lot in the house? If so, how long has it been going on for? It could be an indication of another problem, whether it be that he/she is not being taken out often enough or is marking a spot in the house.
If you find large puddles of urine on the floor it is more likely that the dog had to pee and couldn't or didn't want to go out. With urine marking the dog deposits a smaller amount of urine.
Dogs have very strong instincts, and an unfortunate meaning to that is "once a potty spot ... always a potty spot." Most cleaners remove the smell enough for us humans not to notice it, but for a dog that area is still clearly marked, especially when carpeting is involved. You need to remove the smell from the dog's nose too. This usually takes a bit more than just a carpet cleaner or Lysol.
Enzymatic cleaners are best for this job. The natural enzymes found in cleaners like Nature's Miracle get right down, and break down the bacteria that stays behind causing a "markable" smell.
If you find that your dog is consistently peeing in one spot, I'd suggest purchasing wee pads to put down in the house. This will allow your dog to continue peeing in the spot (assuming it's a spot in the house you're ok with) but on a disposable mat.
I hope this helps. Good luck!