house breaking a 3 year old shitzu

Question
Hi
    I have a 3 year old shitzu that is extremely hard to house break.  We have tried various things including crate training and nothing works.  She continues to soil and urinate in the house.  I have almost brought her to the pound because of this reason.   We have tried to have her ring a bell at the door.  Everytime i bring her out i ring the bell and tell her outside but she goes when she gets outside and then later proceeds to come inside and urinate on the rig or tile/ hardwood floor.  If there is anything you can do to help it would be greatly appreciated.  
                        Jessica

Answer
Jessica-

She needs to be crated when you are not there, and watched like a hawk while you are there. When you take her outside, do not let her back inside until she pees/poops. When she does, praise her and reward her. Bring her out every 3 hours. If you see her start to squat inside, yell NO very loudly, pick her up, and take her outside to finish. Then praise. Remember. Crate when you are not watching her, and when she is out WATCH LIKE A HAWK. Its time to go back to step 1 of crate training. I highly suggest you google crate training and get the general idea of it.

Good luck!