What will you do if your parents become too dependent?

When we grow up and the parents become old, they will pay more attention and turn their focus on us again. They even become dependent--- as if we were parents and they were children. The exchange of roles has changed the communication mode between the two generations. On one hand, it is gentle and warm; on the other hand, there will be lots of contradiction and conflict. It will bring us new a problem: how do we get along well with our parents? How do we help them to spend their life? What will the change bring us?