15 Year Old Dog and Constant Peeing

Question
We have a 15 year old schnasser/terrier.  She used to be such a good dog but for the past 6 months or so she can't seem to stop this darn peeing in the house.  I feel like that is all I do is clean up pee.  Even when I let her outside sometimes she comes back in and pees on the carpet!!!  I don't know if it is just old age or what but I am at wits end with her.  What does a person do with an animal like this????  The only other thing wrong with her is that is is kind of deaf now other than that she has no health aliments.

Answer
Well actually she does have a health ailment. She has a bladder problem but she also has a cognitive function problem. She is most likely unable to control her bladder at all and even if she goes outside, (which she might not be very aware of) she still doesn't know where she is when she goes.

She needs a good check up and some meds to help her control her bladder. Dogs at this age are likely to have tumors inside also that are pressing on her bladder. She isn't trying to be a bad dog, she is simply acting like the 97 + yr old lady that she is.