I haven't tried this, but someone once told me you can place a pad right by the door in the inside and one right outside the door when you first start taking them outside to go potty. According to this person, it works out great when you have a doggy door. I haven't tried that method yet.
My baby goes inside during the day (while I am at work) and goes outside when I am home. I have to always encourage him to go outside though since he is still in the learning phase. When I tell him to do his business, he knows that means to go potty (either inside or outside).
__________________  Kimberly & Stomper |