character interact with background

Player_E

Ill try and explain this and see if it makes sense.

I am working on a side scrolling game that does not let the characters move up and down.

I want to have 2 layers for my game. the foreground and background.
I want the main character and enemies to interact on the foreground, but have points in my game where the main character can jump to the background and avoid interaction with the enemies in the foreground.

hope this makes sense and someone can help me out.

Thanks

Player_E

Now that I think of it the Layer was probably the wrong word to use. lemme put it this way.

My character is walking in the street. when a car comes i want to be able to make him go to the sidewalk so the car cannot contact him.

I do not plan on letting my character move up and down freely. I was thinking of hitting a button and an animation would play moving him to the sidewalk (while he is on the sidewalk I do not want him to be able to advance in the game), then pushing the same button to move him back into the street.

Is this possible?
hope this was a more clear example of what I am trying to do.

Thanks