In technical swaping is interchanging the depths of movieclips.

1. Create two movie clips with instance names "mc1" & "mc2".

2. Then create button both the movie clips with instance "button1" & "button2".

3. Keep both the clips on the stage such a way that they one overlaps the other.. so that we can see the swapping of the clips.

4. Then type the below script in a keyframe in a new layer.

mc1.button1.onRelease=function(){     // button click function
mc1.swapDepths(mc2);                      // swapping clip 1 to clip 2
}
mc2.button2.onRelease=function(){     // button click function
mc2.swapDepths(mc1);                      // swapping clip 2 to clip 1
}